TABLES  FOR 


A.  LIVERSIDGE 


LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 

GIFT    OF 

.PROF.  w.B.   RISING 

» 

Class 


TABLES 


FOR 


QUALITATIVE 
CHEMICAL  ANALYSIS 

ARRANGED  FOR  THE  USE  OF  STUDENTS 


BY 


A.  LIVEESIDGE 

&.A.,  LL.D.,  F.R.S. 

HON.    F.R.S.E.,    ASSOCIATE    OF   THE    ROYAL    SCHOOL    OF    MINES,    LONDON 
PROFESSOR   OF   CHEMISTRY    IN    THE   UNIVERSITY   OF    SYDNEY 


SECOND   EDITION 


.  Eontron 
MACMILLAN    AND    CO.,    LIMITED 


1904 

ALL   RIGHTS    RESERVED 


INTRODUCTION. 


In  these  tables,  primarily  prepared  for  the  use  of  my  own  students,  I 
have  made  an  attempt  to  combine  some  of  the  advantages  of  Quantitative 
methods  with  the  processes  of  Qualitative  Analysis.  It  is  assumed  that  the 
student  using  these  tables  has  been  through  a  preliminary  course  of  practical 
instruction,  including  such  matters  as  glass  working,  the  use  of  the 
blowpipe,  an  instrument  far  too  much  neglected  nowadays,  the  preparation 
of  the  gases  and  of  certain  salts,  etc. 

The  experiments  upon  the  preparation  of  gases,  salts,  etc.,  should  also 
be  carried  out  upon  Quantitative  methods,  i.e.,  the  quantities  of  the  materials 
necessary  for  their  preparation  should  be  calculated  and  weighed  out  or 
measured  by  the  student  himself. 

In  the  case  of  gases,  he  should  also  be  required  to  measure  the  capacity 
of  the  gas  jars  intended  to  be  filled  and  to  correct  their  contents  for  tempera- 
ture and  pressure. 

This  part  of  the  experimental  work  will  thereby  afford  far  better 
training,  be  more  instructive  and  more  interesting  to  the  beginner  than  the 
usual  routine  arithmetical  questions  upon  the  preparation  of  given  volumes 
of  gases  and  the  correction  for  temperature  and  pressure. 

The  educational  value  of  Qualitative  Analysis. — Of  late  it  has  been  usual 
to  condemn  instruction  in  Qualitative  Analysis,  and  to  allege  that  it  is  a 
waste  of  time.  This  may  be  true  if  the  student  is  allowed  to  go  on 
mechanically  testing  mixture  after  mixture  and  is  not  required  to  give 
evidence  that  he  understands  what  he  is  doing ;  to  this  end  he  should 
be  frequently  questioned  as  to  the  reasons  for  making  any  given  experiment, 
and  the  chemical  reactions  it  is  intended  to  bring  about. 

If  the  student  be  required  to  do  his  qualitative  work  intelligently,  the 
time  given  to  it  is  well  spent ;  there  is  probably  more  scientific  training  and 
discipline  involved  in  it  than  in  ordinary  Quantitative  Analysis,  and  if 
properly  taught  it  is  of  great  educational  value. 

The  preliminary  tests  applied  to  complex  mixtures  are  especially  useful 
in  training  the  observing  and  reasoning  powers,  on  account  of  the  way  in 
which  reactions  are  modified  or  interfered  with  when  several  substances  are 
present. 

It  is  not  possible  for  everyone  who  requires  some  knowledge  of  practical 
chemistry  to  devote  time  to  such  matters  as  the  verification  of  the  laws  of 

237403 


INTRODUCTION 

combination,  the  preparation  and  the  purification  of  materials  or  to  undertake 
an  original  research,  but  many,  e.g.,  medical  students,  require  to  have  some 
knowledge  of  Qualitative  Analysis  ;  chemical  and  mining  students  need  a 
larger  and  better  knowledge,  and  it  is  desirable  that  they  should  be  taught 
this  in  an  instructive  manner  and  not  as  mere  test-tubing. 

It  is,  of  course,  not  necessary  for  every  student  to  work  through  the 
reactions  for  all  the  substances  given  in  these  tables ;  typical  ones  can  be 
selected  according  to  circumstances,  e.g.  the  medical  student  need  not 
necessarily  work  through  the  reactions  of  rare  earths. 

Theory  of  Qualitative  Analysis.— It  is  assumed  that  the  student  will  be 
taught  the  principles  of  analysis  and  how  to  use  these  tables,  and  that  he 
will  not  be  left  to  struggle  through  them  unaided  ;  it  is  for  this  reason 
and  because  the  book  is  intended  for  bench  use  that  equations  and  the  usual 
more  or  less  lengthy  explanations  are  omitted. 

The  directions  are  made  as  brief  as  possible,  for  students  when  engaged 
in  practical  work  have  usually  neither  the  time  nor  the  inclination  to  wade 
through  more  or  less  lengthy  descriptions  of  the  methods  of  procedure. 

In  this  laboratory  the  principal  explanations  are  given  in  the  form  of 
lecturettes  and  demonstrations  of  fifteen  or  twenty  minutes  before  the 
practical  exercises  ;  the  class  also  meets  once  a  week  for  one  hour's  tutorial 
instruction  in  the  theory  of  qualitative  analysis,  chemical  equations, 
calculations  and  similar  matters,  and  there  is  a  written  examination  upon 
the  work  at  the  end  of  the  term,  as  well  as  practical  and  theoretical  examina- 
tions at  the  end  of  the  year. 

Weighing  and  Measuring.— By  requiring  the  student  to  work  throughout 
with  weighed  or  measured  quantities,  it  is  necessary  that  he  should  be 
shown,  unless  he  is  already  familiar  with  them,  how  to  use  the  balance, 
burette,  measuring  flasks  and  pipettes  ;  the  small  amount  of  extra  time 
necessary  for  this  will,  however,  be  well  spent. 

The  quantity  of  substance  to  be  examined  can  either  be  weighed  out 
separately  by  each  student,  or  students  can  take  it  in  turns  to  weigh  out  and 
divide  the  portions  for  a  group  of  students. 

The  balance  used  need  not  be  an  expensive  one,  very  good  chemical 
balances,  weighing  to  a  milligram,  can  now  be  obtained  for  less  than  3O/- ; 
if  the  balance  available  is  not  sufficiently  sensitive  for  the  smaller  weights, 
larger  quantities  can  be  weighed  out,  placed  on  glass  or  glazed  paper  and 
divided  by  a  spatula  into  approximately  equal  parts,  just  as  powders  are 
sometimes  divided  by  pharmacists  ;  although  this  would  not  be  quite  so 
satisfactory,  it  would  be  a  great  improvement  upon  the  usual  method 
of  shaking  an  indefinite  quantity  out  of  a  bottle. 


INTRODUCTION 

In  applying  the  colour  tests  for  alkaloids,  a  weighed  quantity,  say  a 
milligram,    should    be   divided   by  a  spatula   into  the  requisite   number  of 
approximately    equal   portions,    as   it   is   quite   unnecessary   to   weigh   the 
fractions  of  a  mgin. 

Although  a  mgm.  may  be  thought  to  be  a  small  amount  to  be  divided 
into  five  or  even  more  portions,  yet  as  the  alkaloids  are  of  comparatively  low 
density  there  is  no  practical  difficulty  in  obtaining  the  reactions  with  such 
quantities  ;  in  poisoning  cases  the  amount  of  alkaloid  to  be  sought  for 
is  usually  small,  it  is  therefore  well  for  the  student  to  acquire  skill  in  working 
with  small  quantities. 

The  amounts  of  material  and  reagents  recommended  have  been  carefully 
tested  and  proved  to  be  ample  for  the  purpose,  and  in  some  instances  even 
smaller  quantities  than  those  mentioned  would  be  sufficient. 

The  amounts  prescribed  are  not  given  in  proportion  to  the  equivalent  or 
molecular  weights  of  the  substances,  because  the  difference  between  them 
and  those  recommended  would  not,  as  a  rule,  be  appreciable. 

The  quantities  to  be  used  are  given  to  promote  accuracy  of  work,  to 
save  time,  and  to  prevent  waste  of  chemicals  ;  usually  an  excessive  quantity 
of  the  substance  to  be  tested  is  used  and  then  ' '  drowned ' '  in  acids  and 
reagents,  which  means  great  waste  of  material  and  a  greater  and  more 
deplorable  waste  of  time  in  filtering  large  volumes  of  solution  and  in 
washing  bulky  and  unwieldy  precipitates.  Further,  by  causing  students  to 
weigh  and  measure  out  the  materials,  they  will  acquire  during  their 
qualitative  work  a  knowledge  of  the  use  of  the  balance  and  of  volumetric 
apparatus  which  will  be  a  useful  introduction  to  quantitative  determinations. 

Graduated  Test  Tubes.— For  simple  tests,  small  test  tubes  of  ^  or 
y%  inch  diameter  are  much  better  than  the  larger  sizes,  for  their  contents  can 
be  boiled  and  otherwise  treated  so  much  more  quickly. 

It  is  as  well  to  have  these  graduated  into  c.c.  ;  the  student  should  do 
this  for  himself  by  running  in  water  from  a  burette  and  marking  the  c.c.  by 
gummed  paper  bands,  with  paint,  or  by  hydrofluoric  acid  ink,  etc.  ;  one 
burette  will  be  sufficient  for  several  students. 

Equivalent  Solutions.  The  acids  and  solutions  used  should  be 
"equivalent"  ones,  so  that  even  the  ordinary  precipitation  and  other 
tests  can  with  the  use  of  graduated  test  tubes  be  carried  out  in  a  more  or 
less  quantitative  manner.  A  table  of  Equivalent  Solutions  is  given  on 
page  115. 

When  an  ''excess  "  of  a  reagent  is  to  be  added,  the  beginner  will  be 
able  to  carry  out  the  operation  much  less  clumsily  than  he  usually  does  with 
ungraduated  test  tubes. 


INTRODUCTION 

Instead  of  being  told  to  add  "  a  few  drops,"  which  to  the  ordinary 
beginner  means  anything  from  5  or  6  drops  to  several  c.c.,  he  should  be 
required  to  add  a  definite  number  of  drops  carefully  counted. 

It  is  usually  the  best  plan  to  deliver  the  drops  from  the  end  of  a  glass 
rod,  although  in  careless  hands  this  may  lead  to  the  reagents  being 
contaminated,  from  the  unrinsed  rods  being  dipped  into  other  bottles. 
Dropping-bottles  and  bottles  with  pipette  stoppers  are  very  useful  for  certain 
reagents,  but  they  cannot  well  be  used  for  all  of  them. 

Mixtures.— The  mixtures  for  analysis  should,  as  far  as  possible,  be  made 
up  in  terms  of  the  molecular  weights  of  the  constituents,  and  in  proportions 
according  to  the  difficulty  of  detecting  them  and  not  haphazard,  as  is  too 
often  the  case. 

After  a  little  experience  with  the  usual  artificial  laboratory  mixtures, 
minerals  and  other  natural  mixtures  should  be  given  wherever  possible,  as 
they  usually  present  greater  difficulties  and  are  of  more  educational  value. 

Preliminary  Tests.— Most  common  substances  can  be  detected  by  the 
preliminary  tests,  and  a  student  should  be  required  to  learn  to  do  so  as  far 
as  possible,  he  then,  if  provided  with  a  blowpipe,  a  candle,  a  few  accessories 
and  reagents,  is  almost  independent  of  a  laboratory,  i.e.,  as  far  as  ordinary 
minerals  and  common  substances  are  concerned ;  the  power  to  work 
with  few  and  simple  materials  is  an  immense  advantage  to  the  explorer 
and  miner. 

If  the  student  finds  a  substance  by  the  wet  processes,  which  he  has 
failed  to  detect  by  the  preliminary  tests,  he  should  be  required  to  repeat  the 
preliminary  tests  until  he  does  find  it,  i.e.,  if  it  is  possible  to  do  so,  if 
impossible  he  should  be  required  to  state  in  his  note  book  the  probable 
reasons  why  it  cannot  be  so  detected,  especially  if  there  be  anything  present 
which  interferes  with  or  masks  the  usual  reactions  of  the  substance  in 
question. 

Blowpipe  Tests.  For  the  blowpipe  tests,  a  portion  of  the  substance  not 
larger  than  a  pin's  head  is  usually  ample  ;  beginners  often  fail  to  get  the 
proper  results  because  they  use  too  much  of  the  substance,  they  often  use 
such  excessive  quantities  as  to  almost  need  a  crucible  and  a  furnace  instead 
of  a  mouth  blowpipe.  Students  should  be  carefully  shown  how  to  make  a 
suitable  cavity  in  charcoal  for  blowpipe  experiments,  how  to  make  a  proper 
platinum  wire  ring  (not  an  irregular  loop)  for  borax  beads,  how  to  mix 
fluxes,  and  other  similar  operations,  and  not  be  left  to  do  them  in  the  usual 
slovenly  way. 

Note  Books.— Students  should  be  required  to  enter  the  date  and  hour 
they  commence  and  finish  a  given  piece  of  work,  and  to  enter  up  a  table  of 


INTRODUCTION 


contents  at  the  beginning  of  the  note  book,  so  that  the  progress  and  range 
of  their  work  can  be  seen  and  kept  in  view  both  by  the  teacher  and  student. 
The  entries  should  as  far  as  possible  be  initialled  by  the  instructor  from  day 
to  day  and  not  at  intervals  of  a  week  or  so. 


I  am  only  too  well  aware  of  the  inherent  defects  in  these,  in  common 
with  other  similar  analytical  tables,  and  mistakes  may  also  have  crept 
in  unawares,  but  I  hope  that  teachers  of  chemistry  into  whose  hands  they 
come  will  not  only  give  the  quantitative  methods  described  a  fair  test,  but 
improve  upon  them. 

A.  UVERSIDGE. 

The  University  of  Sydney. 
December, 


\ 


ERRATA. 


Page  15,  line  25,  for  Fe3"(Fe"'Cy6)3  read  Fe3"(Fe'"Cy6)2. 

,,     18,  lines  2  and  4  from  foot,  for  KsCo(NO2)3  read  K3Co(NO2)6 

„     18,  last  line,  for  Ni(OH)3  read  Ni(OH)2. 

,,  30,  line  8  from  foot,  for  ZrS2O3  read  Th(OH)4  and  S. 

,,  30,  line  12,  for  ZrS2O3  read  Zr(OH)4  and  S. 

,,  30,  line  6  from  foot,  for  Titanum  read  Titanium. 

,,  37,  line  8  from  foot,  for  CuSO4  read  Cu2SO4. 

,,  no,  line  9,  for  'i  gm.  read  i  gm. 


REACTIONS  OF  THE   METALS. 


GROUP  I. — SILVER,  LEAD  AND  MERCURY. 

Silver.    Ag,  107-12. 

DRY  TESTS. — i.  Blowpipe.  Heat  about  "01  gm.  AgNO.,  on  charcoal  with 
Na.2CO3  :  hard  white  malleable  metallic  beads.  Diss.  beads  in  dil.  HNO3, 
add  NaCl  sol.  :  white  AgCl. 

2.  Match  test.     Use  about  '01   gm.    AgNO3  :  Ag  beads. 

WET  TESTS. — Diss.  'i  gm.  of  AgNO3  in  10  c.c.  aq.  and  use  i  c.c.  for 
each  test. 

HC1  :  white  curdy  ppt.  of  AgCl,  insol.  in  dil.  acids,  soluble  in  NH4OH, 
KCN,  Na,S,O3,  also  in  strong  HC1,  NaCl  sol.  etc.  The  AgCl  darkens 
on  exposure  to  light. 

SH,  :  black  Ag,S,   insol.  in  NH4SH. 

NH4OH  :  grey  AgOH.  (Note.  Very  sol.  in  excess.  Apply  the  NH4OH 
from  the  end  of  a  thin  glass  rod  to  the  side  of  the  test  tube  just  above' 
the  AgNO3  sol.  and  let  the  NH4OH  trickle  down  to  the  AgNO3  sol.) 

NaOH  :  grey  brown  AgOH,  insol.  in  excess. 

Na2C03  :  white  Ag2CO3,  insol.  in  excess. 

KI  :  pale  yellow  Agl,  insol.  in  dil.  HNO3  and  almost  insol.  in  NH4OH. 

KBr  :  yellowish  AgBr,  insol.  in  dil.  HNO3,  difficultly  sol.  in  NH4OH, 
readily  in  KCy,  Na.2S,O3,  and  KI. 

KCy  :  white  curdy  AgCy,  readily  sol.  in  an  excess,  in  NH4OH, 
and  in  Na2S2O3  but  insol.  in  dil.  HNO3 ;  on  ignition  :  metallic  silver. 

K2Cr04  :  dark  red  Ag2Cr.O4. 

Copper  foil  :  ppt.  of  grey  metallic  Ag  ;  rub  with  glass  rod  :  metallic 
lustre. 

Lead.    Pb,   205-35. 

DRY  TESTS — i.  Blowpipe.  Heat  about  'or  gm.  Pb2NO3  on  char,  in  the 
reducing  flame  :  soft,  greyish  metallic  beads  which  mark  paper.  In  the 
oxidising  flame  an  incrustation  is  formed,  reddish  brown  when  hot,  yellow 
when  cold. 

2.  Match  test.     Use  about  '02  gm.  Pb2NO3  :   Pb   beads. 

3.  Film  test  :  black. 

WET  TESTS. — Diss.  0*2  gm.  of  lead  acetate,  in  7  c.c.  aq.  (if  cloudy  add 
one  drop  of  acetic  acid). 


10 


MERCURY 


HC1  :  white  crystalline  PbCl2,  insol.  in  NH4OH,  sol.  in  hot  aq.,  rede- 
posited  on  cooling.  Filter  and  pass  SH2  through  the  cold  sol.  :  a  black  ppt. 
of  PbS  which  shows  that  PbCl2  is  somewhat  soluble  in  the  cold,  or  add  KI 
sol.  :  yellow  PbI2. 

SH2  in  the  presence  of  HC1  :  black  PbS,  but  if  too  much  HC1  be  present  a 
reddish  ppt.  of  PbS,PbCl2  comes  down. 

H2S04 :  white  PbSO4,  soluble  in  ammonium  acetate,  in  am.  tartrate,  in 
excess  of  NH4OH  and  in  Na2S2O3. 

NH4OH  :  white  ppt.  (basic  salt),  which  crystallizes  out  on  cooling,  insol. 
in  excess. 

NaOH  :  white  PbO2H2,  sol.  in  excess. 

KI  :  yellow  ppt.  of  PbI2  sol.  in  excess  and  in  hot  aq. 

K2Cr04  :  yellow  PbCrO4,  sol.  in  HNO3  and  in  NaOH. 

Mercury.    Kg,  198-5. 
DRY  TESTS. — i.  Blowpipe.    On  charcoal,  volatilizes. 

2.  Ignition  tube,    (a)  Heated  in  a  dry  tube,  salts  of  mercury  yield  a 
sublimate,     (b]  Heated    in    a   tube   with    soda-lime   or   char,    powder    and 
Na2CO3  :  metallic  globules  or  mirror,  insoluble  in  HC1,  soluble  in  hot  HNO3 
and  in   H2SO4. 

3.  Film  test  :  (a)  Metallic  mirror 

MERCUROUS  SALTS. 


WET  TESTS. — Diss.  '2gm.  HgNO3in 
10  c.c.  aq.  and  a  few  drops  dil. 
HN08. 

HC1  :  white  ppt.  of  HgCl,  blackened 
by  NH4OH. 

SH2  :  black  HgS  mixed  with  Hg,  sol- 
uble in  aq.  regia,  insol.  in 
NH4SH. 

NH4OH  :   black    ppt.* 

NaOH  :  dark  grey  ppt.   Hg2O. 

Na2C03  :  white  ppt.  ;  darkens 

Kl  :   green   Hgl,   sol.   in  excess    of 
KI. 

K2Cr207  :  red  ppt. 

SnCl2 :  white  HgCl,  on  warming :  grey 
metallic  Hg. 


(b)  with  SH2  :  black. 

MERCURIC  SALTS. 
WET  TESTS. — Diss.  '2  gm.  HgCl2  in 
loc.c.  aq 


:  no  ppt. 

:  white,  yellow  and  red  mixtures  of 

HgCl2  and  HgS,  finally  black 

HgS. 

:  white  ppt.  of  (NH2.Hg"Cl). 
:  yellow  HgO. 
:  brown  ppt. 
:  yellow    changing   to    red    HgI2, 

sol.   in  excess  of  KI  and  of 

HgCl2. 
:  no  ppt.   but  a  yellow   ppt.    with 

K2CrO4. 
:  white  ppt.  of  HgCl,  grey  with  an 

excess  of  SnCl2. 


*  Probably  a  mixture  of  mercuric  am.  nitrate  and  free  Hg. 


BISMUTH    AND    COPPER  II 

Acidulate  slightly  with  HC1  and  immerse  a  strip  of  bright  copper  foil  : 
grey  deposit  of  metallic  Hg,  from  both  the  HgNO3  and  HgCl2  sols.,  rub  to 
collect  into  globules  and  to  show  metallic  lustre. 

GROUP  HA. — MERCURY,  L,EAD,  BISMUTH,  COPPER  AND  CADMIUM. 

Bismuth-    Bi,  206-9. 

DRY  TESTS. — i.  Blowpipe.  Heat  '02  gm.  Bi.2O3  on  charcoal  in  inner  flame 
with  Na.2CO3  and  KCy  :  brittle  reddish  metallic  beads  and  orange 
incrustation,  but  yellow  on  cooling. 

2.  Ignition  tube.     Heated  in  tube,  Bi  salts  decompose  and  leave  Bi.2O3, 
orange  when  hot,   yellow  when  cold. 

3.  Match  test.     Use  about  '01  gm.   Bi2O3  :  Bi  beads. 

WET  TESTS. — Diss.  *i  gm.  Bi(NO3)3  in  7  c.c.  aq.,  or  '2  gm.  Bi2O3  in 
5  c.c.  dil.  HC1,  then  dilute  with  aq.  to  7  c.c. 

HC1  :  no  ppt.,  but  on  diluting  very  largely  with  aq.,  white  BiOCl  comes 
down,  insol.  in  KOH  and  in  KHC4H4O(5  (Hyd.  pot.  tartrate). 

SH.2 :  dark  brown  ppt.  of  Bi2S3,  insol.  in  NaOH,  sol.  in  HNO8. 

NH4OH  :  white  Bi  (OH)3,  insol.  in  excess. 

NaOH  :  white  Bi(OH)3,  insol.  in  excess. 

KI  :  (0*1%  soln.) :  brown  BiI3,  very  sol.  in  excess. 

KCy  :  white  Bi(Cy);1>  insol.  in  excess. 

K2Cr207  :  yellow  Bi2(CrO4)3. 

Copper.   Cu,  ea-i. 

DRY  TESTS. — i.  Blowpipe.  Mix  about  '02  gm.  CuO  with  Na.2CO3  and 
KCy,  heat  on  charcoal  in  reducing  flame  :  red  malleable  metallic  particles. 

2.  Match  test :  Cu  beads. 

3.  Borax  bead  :  green,  hot ;  blue,  cold ;  red  in  reducing  flame. 

4.  Flame  test  :  flame,  coloured  green ;  halogen  compounds  of  Cu,  e.g. , 
CuCl2,  give  a  vivid  blue. 

A. — CUPROUS  COMPOUNDS. 

WET  TESTS. — Dissolve  o'i  gm.  Cu2Cl.2  in  2  c.c.  HC1. 

H20  :  white  Cu2Cl2,  changes  to  green  CuCl2,  which  is  soluble. 

KOH  :  yellow  ppt.  of  CuOH,  which  absorbs  O  and  becomes  black 
Cu(OH)2. 

B — CUPRIC  %  COMPOUNDS. 

WET  TESTS. — Diss.  0*2  gm.  CuSO4  in  loc.c.  aq.,  use  i  c.c.  for  each  test. 

HC1  :  no  ppt. 

SH2  :  black  CuS,  nearly  insol.  in  NH4SH  and  NaOH,  sol.  in  strong  HNO;< 

NH4OH  :  pale  blue  ppt,  of  basic  salt,  CuSO4.Cu(OH)2,  sol.  in  excess  to  a 
deep  blue  sol. 


12  CADMIUM   AND   ARSENIC 

NaOH  :  CuO2H2,  .cupric  hydroxide,  turns  black  on  boiling  :  CuO,  but  if 
substances  like  grape  sugar,  tartaric  acid,  tartrates,  urea,  are  present,  a  deep 
blue  solution  forms,  from  which  on  boiling  red  Cu2O  is  precipitated. 

Na2C03  :  greenish  blue  basic  carbonate,  on  boiling  :  black  CuO  or 
3CuO,H2O. 

K4Fc(Cy)6  :  chocolate-coloured  ppt.  of  cupric  ferrocyanide,  Cu.2FeCy6. 

KCy  :  greenish  Cu(Cy)2,  sol.  in  excess.  [NOTE. — SH2  does  not  ppt.  Cu 
from  this  soln.  See  Cd.] 

Metallic  Zn  or  Fe  ppts.  copper  from  solution  as  a  reddish  powder, 
rub  :  bright  copper  particles. 

Cadmium.    Cd,  111-6. 

DRY  TKSTS. — i.  Blowpipe.  Mix  about  '02  gm.  CdSO4  with  Na2CO8  and 
KCy,  and  heat  on  charcoal  in  inner  flame  :  reddish  brown  incrustation 
of  CdO. 

2.    Film  test :  black,  yellow  with  SH2  sol. 

WET  TKSTS. — Diss.   'I  gm.  of  CdSO4  in  5  c.c.  of  aq. 

SH2  and  2  drops  of  HC1  :  yellow  CdS,  insol.  in  £TaOH,  NH4SH,  KCy, 
and  in  (NH4)2CO3 ;  sol.  in  hot  dil.  HC1,  HNO3  and  H2SO4. 

NH4OH  :  white  ppt.  of  Cd(OH)2  sol.  in  excess. 

NaOH  :  white  ppt.  of  Cd(OH)2  insol.  in  excess. 

NH4SH  :  yellow  ppt.  of  CdS. 

KCy  :  white  CdCy2,  sol.  in  excess ;  SH2  ppts.  CdS  from  this  sol.  (See 
Copper,  p.  u.) 

GROUP  HE. — ARSENIC,  ANTIMONY  AND  TIN. 

Arsenic.   As,  74-s 

DRY  TESTS. — i.  Blowpipe.  Mix  with  Na2CO3  and  heat  on  charcoal  : 
white  incrustation  of  As2O3  and  garlic  odour. 

2.  Ignition  tube,     (a)  Heated  in  a  roasting  tube  As  and  arsenical  com- 
pounds give  a  sublimate  of  As2O3 ;   (&)  mixed  with  charcoal  powder  and  soda 
lime  (or  with  charcoal,  dry  Na2CO3   and  KCy)    and  (c)  heated  in  a  bulb 
tube,  they  yield  a  mirror  and  emit  a  garlic  odour. 

Use  'oi  gm.  of  Na3AsO3  for  each  of  the  above  tests. 
NOTE. — Arsenical  fumes   are  poisonous,  therefore   smell   cautiously   by 
wafting  the  fumes  to  the  nose  by  the  hand.  . 

3.  Film  test.     Metallic,  with  SH2  sol.  :  yellow. 

ARSENIOUS  COMPOUNDS. 

WET  TESTS. — Diss.  -i  gm  of  Na3AsO3  in  3  c.c.  of  aq. 
SH2  (and  HC1)  :  yellow  ppt.,  As2S3,  sol.  in  NH4SH,  NaOH  and (NH4)2COS, 
no  ppt.  in  neutral  or  alkaline  solutions. 


ANTIMONY  13 

AgN03  :  lemon  yellow  ppt.  of  Ag3AsO3,  soluble  in  NH4OH  and  in  acids. 
CuS04  :  a  ppt.  of  CuHAsO3  (Scheele's  green). 

ARSENIC  COMPOUNDS. 

WET  TESTS. — Diss.  '2  gm.  Na3AsO4  in  6  c.c.   aq. 

SHe  (and  HC1)  :  warm  and  pass  gas  for  some  time  :  As.2S3  and  S. 

NOTE. — Add  H2SO3  to  reduce  pentad  As  compounds  to  triad  As  com- 
pounds. 

AgN08  :  red  brown  ppt.  of  Ag3AsO4. 

CuS04  :  green  ppt,  CuHAsO4. 

MgS04,  NH4C1  and  NH4OH  ("magnesia  mixture")  :  crystalline  ppt.  of 
MgNH4As04. 

FeCl3  :  yellowish  ppt.  of  FeAsO4. 

(NH4)2Mo04  warm  with  slight  excess  of  cone.  HNO3  :  yellow  ppt.  of  Am, 
arseno-molybdate.  (See  P2O5  tests). 

MARSH'S  TEST. — All  arsenious  and  arsenic  compounds  yield  AsH3  when 
added  to  a  hydrogen  generator,  the  H  flame  acquires  a  grey  colour  (from 
As2O3)  and  deposits  a  metallic  film  of  arsenic  on  cold  porcelain,  and  a  mirror 
of  As  within  the  exit  tube,  if  that  be  heated.  The  zinc  and  acid  must  be 
free  from  As ;  to  prove  this,  ascertain  whether  a  stain  or  mirror  can  be 
obtained  from  them  before  the  As  compound  has  been  added.  The  mirror 
is  sol.  in  NaClO. 

FLEITM  ANN'S  TEST. — Warm  the  As  compound  in  a  test  tube  with  Zn 
and  NaOH  ;  the  AsH3  evolved  blackens  paper  moistened  with  AgNOa  sol. 

REINSCH'S  TEST. — Add  a  strip  of  bright  Cu  foil  and  a  drop  or  two  of 
HC1  to  the  sol.,  let  it  stand  some  time  :  grey  deposit  of  As ;  wash,  dry  and 
heat  in  bulb  tube  :  crystals  of  As2O3. 

Antimony.    Sb,  119-1 

DRY  TESTS. — i.  Blowpipe.  Heat  '02  gm.  Sb2S3  on  char,  with  Na2CO3  : 
white  brittle  metallic  beads  (sol.  in  aq.  regia)  and  white  incrustation. 

2.  Ignition  tube.     Antimony  and  Sb2S3  when  heated  in  a  roasting  tube 
(i.e.,  one  open  at  both  ends)  give  a  white  sublimate  of  Sb.2O3  and  Sb2O4. 

3.  Match  test :  white,  brittle  metallic  beads  of  Sb. 

4.  Film  test.     Velvet  black  ;  orange  with  SH2  sol. 

ANTIMONIOUS  COMPOUNDS. 

WET  TESTS.— Diss.  o'i  gm.  of  Sb2Os  in  5  c.c.  HC1  :  SbCl3. 

SH2  (and  HC1)  :  orange  ppt.  of  antimonious  sulphide  Sb.2S3,  sol.  in  NaOH 
and  in  NH4SH,  and  in  boiling  HC1,  insoluble  in  (NH4)2CO3.  (See  As). 

NH4OH  :  white  ppt.,  Sb2O3,  insol.  in  excess. 

NaOH  :  white  ppt.,  Sb2O3,  sol.  in  excess  to  NaSbO2  (Na metantimonite). 
Boil  with  bright  copper  foil  and  dil.  HC1  :  deposit  of  metallic  Sb  ;  scrape  off 


TIN 


and  diss.  in  HC1  and  dilute  :  white  ppt.  of  SbOCl ;  next  pass  SH2,  the  white 
ppt.  turns  to  orange  :  Sb2S3. 

ANTIMONIC  COMPOUNDS 

Dissolve  o'i  gm.  of  K.  antimonate,  K3SbO4  in  5  c.c.  aq. 

HC1  :  ppt.  sol.  in  excess  of  hot  HC1. 

SH2  :  orange  ppt.  of  Sb2S5,  Sb2S3  and  S.  Soluble  in  alkaline  sulphides 
and  hydroxides,  with  formation  of  antimonates  and  thio-antimonates. 

AgN03  :  white  ppt.  of  Ag3SbO4 ;  (antimonious  salts  free  from  chlorine  :  a 
black  ppt.  of  Ag2O  and  Ag  ;  distinction  between  antimonic  and  antimonious 
salts). 

Antimonic  salts  in  presence  of  HC1  also  set  free  iodine  from  KI ;  anti- 
monious salts  do  not. 

Tin.    Sn,  118-1. 

DRY  TESTS — i.  Blowpipe.  Mix  '02  gm.  SnO2  withNa2CO3  and  KCy  and 
heat  on  char,  in  the  reducing  flame  :  white  malleable  beads,  which  do  not 
mark  paper,  sol.  in  HNO3 ;  the  HNO3  sol.  leaves  a  yellowish  residue 
of  metastannic  acid  Sn5O5(OH)i0  on  evaporation  to  dryness  ;  metastannic  acid 
is  insol.  in  acids  and  in  NaOH,  but  sol.  after  fusion  with  NaOH. 

2.  Match  test :  beads   of  metallic   tin. 

3.  Film  test.     Black,  with   SH2   aq.    :  yellow. 

STANNIC  SALTS,  e.g.,  SnCL,. 
WET  TESTS. — Diss.  "2  gm  SnCl  in 
6  c.c.  aq. 


STANNOUS  SALTS,  e.g.,    SnCl2. 
WET  TESTS. — Boil  *2gm.  tin  with 
5  c.c.  HC1,  dilute  to  10  c.c. 
HC1  :  no  ppt. 
SH2    :    dark    brown    SnS,     sol.     in 

NaOH  (yields  Na  stannite  and 

thiostannite) ';      also   .sol.      in 

yellow  NH4SH,    and   in  cone. 

hot  HC1. 
NH4OH  :  white  ppt.  of  hydrated  stan- 

nous  oxide,  Sn(OH)2. 
NaOH    :    white    ppt.     of    Sn(OH)2, 

sol.   in   excess  to  Na2SnO2,  Na 

stannite. 


HgCl2  :  white  ppt.  of  HgCl ;  boiled 
with  excess  of  SnCl2  :  Hg  as  a 
grey  ppt. 

AuCls  :  ppt.  of  pur  pie  of  Cassius. 


:  no  ppt. 

:  yellow  SnS2,  sol.  in  NaOH. 
(yields  Na  stannate  and  thio- 
stannate) ;  also  sol.  in  NH4HS 


white  ppt.  of  H2SnO3  si.  sol.  in 
excess  and  in  tartaric  acid. 

white  ppt.  of  stannic  acid,  H2SnO« 
sol.  in  excess,  or  of  meta- 
stannic acid  Sn5O5(OH)i0,  diffi- 
culty sol.  in  NaOH  and  in 
acids. 

no  change. 


no  change. 


IRON  AND  ALUMINIUM  15 

GROUP  IIlA. — IRON,  ALUMINIUM  AND  CHROMIUM. 

Iron.    Fe,  55-6. 

DRY  TESTS. — i.  Blowpipe.  Heat  '02  gm.  of  FeSO4  on  char,  with 
NaoCOs,  :  black  magnetic  particles.  Crush  and  wash  in  agate  mortar ; 
pick  out  the  magnetic  particles  with  a  magnetised  penknife  blade.  Place  on 
filter  paper,  add  HC1  :  yellow  stain,  add  K*FeCy6  :  Prussian  blue. 

2.  Match  test :  Same  as  on  char. 

3.  Borax  bead  :  <bottle  green  in  inner  flame  ;    reddish  in  outer   flame 
while  hot,  but  yellow  or  colourless  when  cold. 

FKRROUS  SALTS.  FERRIC  SALTS. 

WET  TESTS. — Diss.    0*2    gm.  WET  TESTS. — Diss.   *2  gm.   FeCl3 

FeSO4  in  loc.c.  aq.  in  10  c.c.  aq. 

NH4OH    :    greenish    ppt.    Fe(OH)2,  :  reddish  ppt.    of  Fe(OH)8,  in    ab- 

rapidly  oxidizes  and  blackens.  sence  of  organic  matter. 

NaOH  :  greenish  ppt.  Fe(OH)2,  rapidly  :  reddish  ppt.   of  Fe(OH)3,  in    ab- 

oxidizes  and  blackens.  sence  of  organic  matter. 

SH2  :  no  ppt.  :  S  is  precipitated. 

NH4SH  :  black  ppt.  FeS.,  :  FeS  and  free  S. 

(NH4)2CO*  :  greenish  ppt.,  FeCO3.  :  Red  ppt.  of  Fe(OH)3. 

K4FeCy6  :   pale    blue,      K2Fe,FeCy6,  :  Prussian  blue,  Fe4(FeCy6)3. 

which     darkens    and    becomes 

Fe4(FeCy6)3. 

K3FeCy6  :  deep     blue      (TurnbulFs)  :  no  ppt. 

Fe3"(Fe"'Cy6)3. 

KCNS  :  no  change,  the  slightest  trace  :  blood  red  sol.  * 

of  ferric  salt  gives  a  red  colour 

Na2HP04 :  bluish  ppt.  :  reddish  white  Fe"'(PO4). 

Tannie  Acid  :  blue  black  ppt.  :  blue  black  colour  (ink). 

Ferric  salts  are  reduced  and  decolourized  by  Zn  and  HC1,  by  SO2, 
SnCl2,  and  other  reducing  substances. 

Aluminium.    Al,  26-9. 

DRY  TESTS. — Blowpipe.  Strongly  heat  on  char,  or  on  Pt  wire  :  white 
highly  luminous  residue.  Moisten  with  Co2NO3  and  re-heat  :  blue 
mass.  If  the  substance  be  in  solution,  moisten  a  scrap  of  filter  paper  with 
it,  dry  and  ignite  on  Pt.  wire  in  bunsen  flame;  moisten  residue  with  Co2NO3 
and  again  ignite  :  blue  residue. 


*  Sol.  in  ether,  destroyed  by  HgCl2,  but  not  by  HC1,  the  red  colours  of  ferric  for- 
mate and  acetate  are  destroyed  by  dil.  HC1,  the  red  colour  with  meconates  is  not 
destroyed  by 


1 6  CHROMIUM   AND   CHROMIC   ACID 

WET  TESTS. — Diss.  o'2  gm.  of  alum  KAl2SO4,i2H2O  in  5  c.c.  aq. 

NH4OH  :  white  gelatinous  A1(OH)3>  practically  insol.  in  excess  and  in 
NH4C1. 

NaOH  :  gelatinous  A1(OH)3,  sol.  in  excess  to  Na3AlO3,  and  not  reprecip- 
itated  on  boiling  ;  reprecipitated  by  adding  HC1  and  NH4OH  and  boiling. 

NH4SH  :  white  gelatinous  A1(OH)3  and  SH2  evolved. 

(NH4)2C03  :  white  gelatinous  A1(OH)S  and  CO2  evolved. 

(NH4)3P04  :  white  A1PO4,  sol.  in  NaOH,  KOH  and  sparingly  in  NH4OH, 
but  insol.  in  NH4C1. 

Chromium.    Cr,  51-7. 

DRY  TESTS.— Blowpipe,  (a)  Borax  bead  :  emerald  green  in  both 
flames,  (b)  Fused  on  Pt  foil  with  Na2CO3  and  KNO3  :  yellow  K  and  Na 
chromates.  Diss.  in  acetic  acid,  add  Pb  acetate  :  yellow  ppt.  of  Pb  chromate. 

WET  TESTS. — Diss.  "2  gm  chrome  alum  (KCr2SO4.i2H2O)  in  5  c.c.  aq. 

NH4OH  :  green  Cr(OH)3,  insol.  in  excess  on  boiling. 

NaOH  :  green  Cr(OH)3,  sol.  in  excess  to  a  green  or  violet  colour,  but  re- 
precipitated  on  boiling. 

NH4SH  :  green  ppt.  of  Cr(OH)3  and  SH2  evolved,  insol.  in  excess. 

(NHOaCOs  :  green  ppt.  of  Cr(OH)8. 

Cl  aq.  or  Br  aq.  in  the  cold  oxidizes  Cr  salts  to  chromates. 
Cr  forms  both  basic  and  acid  salts. 

BASIC.  ACID. 

CrO  :  chromous  salts.  Chromates  contain  CrO3  (yellow). 

Cr2O3  :  chromic  salts,  mostly  green.         Bichromates  contain  2CrO:j  (red). 

If  the  Cr  be  present  as  an  acid  radicle  (CrO3)  it  must  be  reduced  to  the 
basic  condition  by  boiling  with  cone.  HC1  or  with  H2SO3  before  applying  the 
above  wet  tests. 

Chromic  Acid.    H2Cr04 

DRY  TESTS. — The  same  as  for  basic  Cr. 

WET  TESTS. — Diss.  o'i  gm.  of  K2Cr2O7  in  5  c.c.  aq.  and  divide  into  5 
parts. 

HC1 :  deep  red  colour,  becomes  green  (CrCl3)  on  boiling  with  alcohol  (or 
SO2)  or  on  passing  SH2  through  it. 

BaCl2  :  yellow,  BaCrO4,  sol.  in  acids. 

AgN03  :  dark  red  Ag2CrO4. 

Pb2C2H302 :  yellow  PbCrO4. 

H202  (in  ether)  and  one  drop  of  dil.  HC1,  shake  :  deep  blue  solution. 
(Due  to  the  unstable  Cr2O-.) 


ZINC,    MANGANESE   AND   NICKEL  17 

GROUP  IV. — ZINC,  MANGANESE,  NICKEL  AND  COBALT. 

Zinc.    Zn,  64-9. 

DRY  TESTS — i.  Blowpipe.  Heated  on  char,  in  inner  flame  with  NaKCO3, 
Zn  salts  yield  a  yellow  incrustation  of  ZnO,*  white  when  cold  ;  moisten  with 
Co2NO3  and  again  heat  before  blowpipe  :  green  residue. 

2.  Film  test. — Black,  becomes  white  with  SH2  sol. 

WET  TESTS. — Diss.  o'l  gm.  ZnSO4  in  5  c.c.  aq. 

NH4OH  •:  white  ppt,  of  Zn(OH),,  in  absence  of  NH4  salts. 

KOH  or  NaOH  :  white  ppt.  Zn(OH)2,  which  is  sol.  in  an  excess  of  re- 
agent ;  add  NH4SH  :  white  ppt.  of  ZnS. 

NH4SH  :  white  ppt.  of  ZnS  insol.  in  excess,  NH4OH  and  NH4C1  facilitate 
its  precipitation  from  dil.  sols.  Sol.  in  HC1,  HNO3,  and  H2SO4,  but  insol.  in 
acetic  acid.  (See  Mn). 

(NH4)2C03 :  white  basic  Zn  carbonate,  ZnCO3,3Zn(OH)3,  sol.  in  excess. 

KCy  :  white  ppt.  of  Zn(Cy)2,  sol.  in  excess,  from  which  it  is  precipitated 
by  Na-2S  as  ZnS,  but  not  by  NH4SH. 


Manganese.    Mn,  54-6. 

DRY  TESTS — Blowpipe.  (a)  Borax  bead  :  an  amethyst  colour  in  the 
oxidising  and  a  colourless  bead  in  the  reducing  flame.  (&)  Fuse  '01  gm. 
MnO2  with  a  little  Na.2CO8  and  KNOs  on  Pt  foil  or  wire  :  green-coloured 
mass  of  K  and  Na  manganates  ;  diss.  this  in  a  little  very  dilute  H2SO4  :  red 
sol.  of  Na  and  K  permanganates. 

WET  TESTS. — Diss.  o'i  gm.  MnSO4  in  5  c.c.  aq. 

NH4OH  :  white  ppt.,  Mn(OH),,  sol.  in  NH4C1. 

NaOH  :  white  ppt.  of  Mn(OH)2,  insol.  in  excess  ;  rapidly  oxidizes  and 
turns  to  brown  Mn2O3,H2O. 

NH4SH  :  pinkish  ppt.  of  MnS ;  the  fresh  ppt.  is  sol.  in  acetic  acid. 

Na-jCOa  :  white  MnCO3,  sol.  in  NH4C1,  oxidizes  and  becomes  brown. 

KCy  :  white  Mn(Cy)2,  soluble  in  excess. 

Nickel.    Ni,  58-3. 

DRY  TESTS.— Blowpipe,  (a)  Borax  bead  :  grey  in  inner,  reddish  in 
outer  flame  ;  a  little  KNO3  renders  the  bead  purple,  (d)  On  char,  with 
Na2CO3,  or  on  match  :  black,  slightly  magnetic  particles.  Use  magnetised 
penknife  blade. 


*  Zinc  is  volatile,  but  ZnO  is  not. 


1 8  NICKEL    AND    COBALT 

WET  TESTS. — Diss.  o'i  gm.  of  NiSO4  in  7  c.c.  of  aq. 

NH4OH  :  light  green  ppt.>  Ni(OH)2,  sol.  in  excess  to  a  blue  solution. 

NaOH  :  light  green  Ni(OH)2  insol.  in  excess,  but  sol.  in  NH4  salts,  and 
in  acids. 

NH.SH  :  black  ppt.,  NiS,  insol.  in  acetic  and  hydrochloric  acids,  slightly 
sol.  in  NH4SH,  and  in  NH4OH.  The  sol.  is  brown. 

NaCIO  sol. ,  boil  :  black  Ni(OH)3. 

(NH4)2C03  :  green  ppt.,  basic  NiCO3,  sol.  in  excess. 

KCy  :  greenish  ppt,  Ni(Cy)2,  sol.  in  excess  to  a  brown  sol.  of  2KCy, 
NiCy2;  reprecipitated  by  acids  (see  Co);  to  the  sol.  in  KCy  add  Br  aq. 
until  of  a  permanent  brown  colour ;  warm  :  black  ppt.  of  Ni(OH)3. 

K4FeCy6 :  greenish  ppt. ,  NiaFeCyc. 

Cobalt.    Co,  58*56. 

DRY  TESTS. — Blowpipe,  (a)  Borax  bead  :  blue  in  ,ooth  reducing  and 
oxidizing  areas,  (b)  On  char,  with  Na2CO3,  or  with  match  test  :  black  mag- 
netic particles.  Use  magnetised  penknife  blade. 

WET  TESTS. — Diss.  -2  gm.  of  Co2NO3  in  7  c.c.  aq. 

NH4OH,  in  absence  of  NH4C1,  :  blue  ppt.  of  basic  salt,  sol.  in  excess  to  a 
brown  sol.,  which  momentarily  becomes  purple  on  boiling. 

NaOH  :  a  blue  ppt.  of  basic  salt,  Co(OH)2,Co2NO3,  insol.  in  excess, 
becomes  green  on  standing,  and  pink,  (Co(OH)2)  or  brown  on  warming, 
dissolves  in  (NH4);CO3  (after  washing)  to  a  deep  purple  sol. 

NH4SH  :  a  black  ppt.  of  CoS  difficultly  sol.  in  dil.  HC1  or  H2SO4,  but 
readily  sol.  in  warm  aqua  regia. 

(NH4)oC03  :  rose  coloured  ppt.,  sol.  in  excess. 

KCy  :  brown  ppt.  of  CoCy2,  sol.  in  excess  to  2KCy,CoCy2;  when  boiled 
with  a  drop  of  HC1  to  set  free  HCy,  K3CoCyc  (pot.  cobalti-cyanide)  is 
formed,  from  which  Co(OH)3  is  not  precipitated  by  HC1  nor  by  NaCIO. 
(Compare  NiCy2).  To  separate  Co  and  Ni  by  this  reaction,  add  KCy 
until  the  ppt.  only  just  redissolves,  then  add  two  or  three  drops  of  acetic 
acid,  boil  for  three  minutes ;  cool,  filter  off  any  ppt.  which  forms, 
make  alkaline  with  NaOH,  add  Br  aq.  until  the  sol.  remains  yellow  to 
brown  in  colour,  warm  :  black  ppt.  of  Ni(OH)3.  Filter,  evaporate  filtrate 
and  test  for  Co  by  borax  bead.  <* 

K4FeCy6  :  a  dark  green  ppt.  of  Co2FeCye. 

KN02  and  acetic  acid  to  a  neutral  sol.  :  bright  yellow  crystalline  ppt.  of 
K8Co(NO2)3  (pot.  cobaltinitrite).  This  reaction  also  serves  for  the  separation  of 
Co  from  Ni  ;  add  two  or  three  c.c.  of  alcohol  and  shake  the  mixture,  let 
stand  for  fifteen  or  twenty  minutes,  filter  off  the  KsCo(NO2)3,  and  add  NaOH 
to  the  filtrate  :  Ni(OH)s. 


BARIUM,     STRONTIUM     AND    CALCIUM  19 

GROUP  V. — BARIUM,  STRONTIUM  AND  CALCIUM. 

Barium.    Ba,  136-4. 

DRY  TKST. — Ba  salts  colour  the  bunsen  flame  pale  green,  especially 
when  moistened  with  HC1. 

WKT  TKSTS. — Diss.  0*1  gm  Bad,  in  5  c.c  aq. 

(NHO-jCOs  :  white  ppt.  of  BaCCX,  sol.  in  diL.HCl,  slightly  soluble  in 
NH4C1. 

CaS04  or  other  sulphates  or  dil.  H2SO4  :  an  immediate  ppt.  of  BaSO4 
even  in  dil.  sols.  Insol.  in  dil.  acids  and  alkalis. 

(NH4)2C204  :  white  granular  ppt.  of  BaC2O4. 

K2Cr04  :  pale  yellow  ppt.  of  BaCrO4  from  even  dil.  sols.  ;  sol.  in  HC1  and 
HNO3 ;  insol.  in  acetic  acid  ;  SrCrO4  and  CaCrO4  are  sol. 

H2SiF,;  gives  a  white  crystalline  ppt.  of  BaSiF6,  hastened  by  the  addition 
of  alcohol ;  Ca  and  Sr  salts  are  not  precipitated  by  H2SiF6. 

Strontium.    Sr,  86-94. 

DRY  TEST. — Sr  salts  colour  the  flame  red. 

WET  TESTS. — Diss.  o'  i  gin.  of  SrCLj  in  5  c.c.  aq. 

(NHOaCOs  :  white  ppt.  of  SrCO3. 

H2S04  (dil.)  or  a  sol.  sulphate  throws  down  white  SrSO4.  If  CaSO4  is 
used  or  the  sol.  be  dilute  the  ppt.  will  take  some  time  to  form  ;  hastened  by 
boiling  with  (NH4)2SO4,  in  which  CaSO4  is  soluble. 

Na2HP04  ;  a  white  ppt.  of  Sr32PO4. 

(NH4),C,04  :  white  ppt.  of  SrC,O4. 

K2Cr04  :  pale  yellow  ppt.  of  SrCrO4,  sol.  in  acetic  and  other  acids.     • 

Calcium.    Ca,  39-8. 

DRY   TEST. — Ca   salts   colour   the  flame  orange  red. 

WET   TESTS. — Diss.  *i  gm.  CaCl2  in  5  c.c.  aq. 

(NH4)2CO;<,  in  the  presence  of  NH4C1,  gives  a  white  ppt.  of  CaCO3.  Ignite 
ppt.  on  Pt  wire  :  CaO  ;  place  this  residue  on  moist  red  litmus  paper  :  blue. 

H2S04,  or  a  sulphate  (except  CaSO4)  :  white  ppt.  of  CaSO4  from  strong 
sols.,  or  from  weak  ones  on  adding  alcohol. 

Na2HP04  and  NH4OH  :  bulky  white  ppt.  of  Ca3P2OM,  sol.  in  HC1  and 
HNO8. 

(NH4)2C204  :  white  ppt.  of  Ca  oxalate  (CaC2O4)  insol.  in  acetic  acid ;  sol. 
in  HC1. 

K2CrOi,  no  ppt.  unless  the  solution  is  very  strong. 


20  MAGNESIUM,      POTASSIUM     AND     SODIUM 

GROUP    VI. — MAGNESIUM,    POTASSIUM,    SODIUM,    AMMONIUM 
AND   LITHIUM. 

Magnesium.    Mgy  24-18. 

DRY  TEST. — Blowpipe.    Mg  salts  on  char,  or  Pt  wire  :  a  white  luminous 
residue,  moisten  this  with  Co2NO3  and  heat  strongly  :  pink  residue. 

WET  TESTS. — Diss  'i  gm.  MgSO4  in  4  c.c.  aq. 

NH4OH  :  white  gelatinous  ppt.  of  Mg(OH)2  i.e.,  in  the  absence  of  NH4C1, 
otherwise  soluble  double  salts  are  formed. 

?KOH,  NaOH,  Ca(OH)2,  and  Ba(OH>2  throw  down  Mg(OH),  in  the  absence 
of  NH4  salts.  Mg(OH)2  is  only  slightly  soluble  in  aq. 

(NH4)2C03  :  white  crystalline  ppt.  of  Mg(NH4),2CO,  (after  some  time)  if 
NH4  salts  are  absent. 

Na2HP04  in  the  presence  of  NH4OH  and  NH4C1  :  crystalline  ppt.  of 
Mg(NH4)PO4,  especially  when  stirred  or  shaken.  Dilute  solutions  should  be 
allowed  to  stand  some  time. 


Potassium.    K,  38-86. 

DRY  TESTS. — i.  K  salts  colour  the  bunsen  flame  lilac  to  violet;  if  the 
flame  be  yellow  from  the  presence  of  sodium  examine  it  through  blue  glass 
or  an  indigo  prism,  so  as  to  cut  out  the  yellow  rays  ;  if  lithium  be  present, 
view7  the  flame  through  four  or  five  thicknesses  of  blue  glass. 

2.  Confirm  with  spectroscope. 

3.  Blowpipe.     On  charcoal,  K  salts  fuse  and  sink  into  the  charcoal,  and 
colour  the  flame  greyish  or  pale  lilac. 

WET  TESTS. — Diss.  '2  gm.  KC1  in  3  c.c.  aq. 

Chloroplatinie  Acid,  ''Platinum  chloride,"  (H2PtClfi)  :  a  yellow  crystal- 
line ppt.  of  K2PtCl6,  insol.  in  acids  and  in  alcohol ;  sol.  in  KOH. 

Tartarie  Acid,  H2C4H4Oti,  or  sodium  hydrogen  tartrate  NaHC4H4O6  : 
white  crystalline  ppt.  of  KHC4H4O6  from  neutral  solutions  ;  its  formation  is 
hastened  by  stirring  and  shaking,  and  by  the  addition  of  alcohol. 

H2SiF6  :  a  gelatinous  ppt.  of  K2SiF6,  sol.  in  aq.  (i  in  about  800);  insoluble 
in  alcohol. 


Sodium.    Na,  22-88. 

DRY  TEST. — Na  salts  colour  the   bunsen    flame  yellow ;    seen  through 
blue  glass  or  an   indigo  prism  it  appears  colourless. 

WET  TESTS. — There  are  no  satisfactory  tests  for  sodium  in  solution. 


AMMONIUM,    LITHIUM    AND    TUNGSTEN  21 

Ammonium.  (NH4) 

DRY  TESTS. — i.  Ignition  tube.  Most  ammonium  salts  when  heated  in  a 
dry  tube  yield  a  white  sublimate,  either  with  or  without  the  evolution  of 
NH3,  which  is  recognised  by  its  smell  and  the  bluing  of  red  litmus. 

2.  Ammonium  salts  warmed  with  Ca(OH).2  or  NaOH  sol;  :  NH8  gas. 

WET  TESTS. — Diss.  '2  gm.  NH4C1  in  3  c.c.  of  aq. 

Chloroplatinie  aeid,  "Platinum  chloride,"  H2PtCl6  :  yellow  ppt.  of 
(NH4)3PtCl6  similar  to  that  from  K  salts  ;  ignite  the  (NH4)2PtCl6  on  porce- 
lain :  residue  of  grey  spongy  platinum. 

Tartarie  aeid,  H2C*H4O6  :  white"  crystalline  ppt.  of  (NH4)HC4H4O(i ; 
ignite  :  carbon  free  from  alkaline  reaction. 

Nessler's  test  for  minute  traces  of  NH3  :  a  yellow  or  brown  colouration 
(due  to  NHg.2I,HaO).  Test  for  NH3  in  the  distilled  aq.  used. 

Lithium.    Li,  6-98. 

DRY  TESTS. — Li  salts  colour  the  bunsen  flame  crimson  ;  Na  changes  it  to 
orange,  but  the  Li  is  recognisable  if  the  flame  be  viewed  through  the  thinner 
parts  of  the  indigo  prism.  A  silicate  must  be  fused  with  CaSO4,  and.LisPC^ 
moistened  with  HC1  to  obtain  the  flame  colouration.  Li  is  easily  recog- 
nised in  the  spectroscope  by  the  single  red  and  orange  bands. 

WET  TESTS. — Diss.  o.i  gm.  of  LiCl  in  3  c.c.  of  aq. 

NaJHP04  and  NaOH,  boil  :  a  white  crystalline  ppt.  of  2Li8PO4,H2O.  If 
traces  only  of  Li  are  present,  add  Na<2HPO4  and  NaOH,  and  evaporate  to 
dryness  and  wash  the  residue  with  dil.  NH3. 

Na2C08,  (K.2CO3  or  (NH4).2CO3)  with  an  equal  vol.  of  alcohol  :  ppt.  of 
Li^COa.  Lithium  in  waters.  Concentrate,  add  Ba(OH).2  and  cool ;  then  add 
(NH^COs  and  filter  ;  to  the  filtrate  add  Na3HPO4,  take  up  with  a  small 
quantity  of  aq.,  residue  :  Li  i  phosphate.  Confirm  by  the  flame  test.  Li 
differs  from  K  and  NH4  by  not  being  precipitated  by  H2PtCl6  or  by 
H2C4H4O(i.  LiCl  can  be  separated  from  KC1  and  NaCl  by  a  mixture  of 
absolute  alcohol  and  ether,  in  which  it  is  insoluble. 

RARER  METALS  OF  GROUP    I. — TUNGSTEN,  THALLIUM  AND  NIOBIUM. 

Tungsten  or  Wolfram.    W,  182-6. 

DRY  TESTS. — Blowpipe.  (a)  Heat  '02  gm.  Na.2WO4  on  char,  with 
Na.2CO3  and  KCN  :  black  impure  tungsten.  (£)  Mieroeosmie  salt,  in  outer 
flame  :  colourless  or  yellow  bead  ;  in  inner  flame  :  blue  bead  ;  re-fused  with 
a  little 'powdered  FeSO4  :  blood  red  when  cold. 


22  THALLIUM 

WET  TESTS. — Diss.  o'i  gm.  Na.2WO4  in  5  c.c.  aq. 

HC1,  HN03  or  H2S04  :  white  ppt.  of  H.2WOi ;  yellow  on  boiling,  sol.  in 
NH4OH ;  add  fragment  of  zinc  :  blue  colour. 

SH2  :  no  ppt.,  but  H2WO4  is  reduced  to  the  blue  W.2O,> 

HC1  and  Zn  :  the  deep  blue  W.2O5,  turning  to  brown  WO2. 

SnCla  in  neutral  sol.  :  yellow  ppt.  of  WO.2  (?)  add  HC1  and  warm  :  blue. 

NEUSH  :  no  ppt.  until  HC1  is  added,  the  sol.  turns  blue  and  a  brown  ppt. 
of  WS3  forms  ;  readily  sol.  in  NH4SH. 


Thallium.    Tl,  202-6. 

Thallium  is  partly  thrown  down  as  chloride  in  Group  I  with  Pb,  etc., 
also  in  Group  II  with  As,  and  partly  as  sulphide  in  Group  IV.  Examine 
As.2Sa  for  Tl,  as  Tl  may  come  down  with  it. 

DRY  TKSTS. — Flame  test  :  strong  green  colour,  and  one  bright  green 
band  in  the  spectrum. 

THAUJOUS   COMPOUNDS. 

WET  TESTS.— Diss.  *i  gm,  T1.2SO4  in  7  c.c.  aq. 

HC1  :  white  ppt.  of  T1C1,  sol.  in  aq.  regia  ;  is  not  blackened  by  light 
Slightly  sol.,  hence  not  formed  in  dil.  solutions. 

SH2 :  black  T12S,  only  partly  precipitated,  except  in  acetic  acid  sol. 

KI  :  yellow  ppt.  Til,  nearly  insol.  in  aq.,  more  sol.  in  KI. 

H2PtCl6  :  orange  ppt.,  Tl.2PtCl6  slightly  sol.  in  aq. 

NH4SH  :  black  ppt.,  clots  on  boiling,  insol.  in  NH4OH,  in  alkaline  sul- 
phides and  in  KCN ;  oxidised  by  the  air  to  T1.2SO4,  which  is  readily  sol.  in 
mineral  acids. 

K2Cr04  :  yellow  Tl.2CrO4  insol.  in  cold  HNO3. 

Zn  :  metallic  Tl. 

THALLIC  COMPOUNDS. 

WET  TESTS. — Diss.  'oi  gm.  T1C13  in  5  c.c.  aq. 

HC1  :  no  ppt. 

SH2  :  reduces  thallic  to  thallious  salts,  with  separation  of  S. 

KI  :  ppt.  of  yellow  Til,   and  free  I. 

K2Cr04  :  no  ppt. 

H2C204  :  white  ppt.  of  Tl  oxalate. 

To  detect  Tl  in  pyrites,  etc.,  and  in  the  residue  left  by  Zn  when  dis- 
solved in  HC1,  diss.  in  aq.  regia,  add  H.2SO4  and  boil  off  the  HNO3,  add 
Na2SO3  to  reduce  to  ferrous  and  thallious  salts,  then  add  KI,  when  yellow 
Til  is  precipitated. 


NIOBIUM,    OSMIUM    AND    PALLADIUM  23 

Niobium  or  Columbium.    Nb,  93-3. 

DRY  TEST. — Blowpipe.     Microcosmic   salt  :  colourless  bead  in  the  OF 
while  hot,  in  the  RF  :  violet,  blue,  or  brown ;  add  a  little  FeSO4  :  red  colour. 
WET  TESTS. — Diss.  *oi  gm.  KNbO3  in  5  c.c.  aq. 
H2S04  and  other  mineral  acids  :  ppt.  of  Nb(OH)a. 
NH4OH  or  NH4SH  :  ppt.  of  Nb(OH)3,  sol.  in  HF. 
K4FeCye  and  two  drops  of  HC1  :  red  ppt. 
K3FeCyc,  :  yellow  ppt. 
Zn  and  HC1  :  blue  ppt.  which  changes  to  brown. 

RARER  METALS  OF  GROUP  HA. — OSMIUM  AND  PALLADIUM. 

Osmium.    Os,  189-6. 

DRY  REACTION. — Volatilizes  at  a  very  high  temperature  as  OsO4 
without  fusion. 

WET  TESTS. — Diss.   '01  gm.  OsO4  in  5  c.c.  aq. 

SH2  (in  acid  solutions)  :  brown  black  ppt.  of  OsS. 

Alkalis  and  their  carbonates  :  reddish  brown  ppt.  of  Os(OH)4. 

Tannie  acid  (or  alcohol)  and  HC1  reduce  it  to  the  blue  osmious  chloride, 
OsCL. 

Indigo  solution  is  bleached. 

Na2S03  :  deep  violet  colour,  and  a  ppt.  of  blue  osmious  sulphite  gradually 
forms. 

Palladium.    Pd,  ios-7. 

DRY  TEST. — Heat  a  small  particle  of  PdCL2  on  porcelain  :  a  residue  of 
Pel.  All  Pd  salts  yields  Pd  on  ignition. 

PALLADIOUS  SALTS. 

WET  TESTS. — Diss.  -05  PdCl2  in  10  c.c.  aq.  and  two  drops  HC1. 

SH-2  or  NH4SH  :  black  ppt.  of  PdS  in  neut.  alk.  and  acid  solutions,  insol. 
in  NH4SH,  but  sol.  in  hot  HC1  or  aq.  regia. 

NH4OH  :  pink  ppt.  of  PdCl.2.2NH3,   sol.   in  excess. 

HgCy2  :  yellowish  gelatinous  PdCy2,  slightly  sol.  in  HC1,  readily  in 
NH4OH  ;  heated  :  spongy  Pd.  (Characteristic.) 

KI  :  black  ppt.  of  PdI2,  sol.  in  excess  of  KI.     (Characteristic.) 

KC1  :  brown  red  2KCl,PdCl2,  on  standing. 

NH4C1  :  no  ppt.     (Difference  from  Pt). 

Iodine  (tincture)  forms  a  black  stain  on  Pd,  but  not  on  Pt. 

SnCl2  :  brown-black  ppt.,  sol.  in  HC1  to  a  green  sol. 


24  GOLD 

KOH  :  light  brown  basic  salt,  sol.  in  excess. 

Na>S203  (a  few  drops  in  NH4OH)  :  pale  yellow  solution  ;   on  boiling  be- 
comes black. 

PALLADIC  SALTS. 

WET  TESTS. — Diss.    i   mgm.  of  PdCl4  in  2  c.c.   aq. 

KOH  :  brown  ppt.  of  Pd(OH)4.    Boil  :  black  PdO>. 

KC1:  bright  red  crystalline  ppt.   of  2KCl,PdCl4  or  K.2PdCl(;. 


THE  RARER  METALS  OP  GROUP  HB. — GOLD,  PLATINUM,  IRIDIUM, 
MOLYBDENUM,  SELENIUM  AND  TELLURIUM. 

Gold.    Au,  195-7. 

DRY  TEST. — Blowpipe.  Heated  on  char,  or  on  match,  all  gold  com- 
pounds are  decomposed  and  the  metal  is  left ;  if  the  charcoal  or  match  end 
be  ground  in  an  agate  mortar  and  the  charcoal  be  very  carefully  washed 
away,  so  as  not  to  float  off  gold  with  it,  very  minute  traces  of  gold  can  be 
detected  in  this  way.  The  spangles  of  gold  are  insol.  in  H2SO4,  in  HC1  free 
from  Cl,  and  in  HNO3  free  from  N.  oxides ;  sol.  in  aq.  regia. 

WET  TESTS. — Diss.  -01  gm.  NaAuCl4,2H2O  (photographers'  "  gold 
chloride  ")  in  10  c.c.  aq. 

SHo  in  cold  sols.  :  black  Au.2S3  (auric  sulphide). 

SH2  in  hot  sols.  :  brown  Au2S  (aurous  sulphide)  mixed  with  free  gold,  if 
long  boiled  the  whole  is  reduced  to  metallic  gold.  Both  Au>S  and  Au.2S3  are 
sol.  in  aq.  regia,  in  yellow  NH4SH,  and  in  yellow  Na2S. 

FeS04  :  ppt.  of  metallic  gold. 

S02  :  ppt.  of  metallic  gold. 

H2C204  on  warming  :  ppt.  of  metallic  gold. 

NH4OH  :  pale  orange  ppt.  of  fulminating  gold  (Au,  N,  and  NH3)  sol.  in 
excess.  This  ppt.  explodes  with  great  violence,  especially  when  dried  and 
heated. 

SnCl2  and  three  drops  of  FeCl3  :  purple  of  Cassius. 

P  dissolved  in  ether,  :  red  or  purple  colour,  even  in  exceedingly  dil. 
AuCl3,  say  one  part  of  Au  in  1,000,000  of  aq. 

Zn  and  most  metals  precipitate  gold  from  its  solutions. 

Iodine  tincture  readily  dissolves  out  traces  of  gold  from  quartz,  etc. 
Agitate  five  or  ten  grammes  of  the  finely-powdered  mineral  with  a  tincture 
of  iodine,  let  stand,  dip  a  strip  of  white  filter  paper  into  the  clear  liquid,  dry 
and  burn  ;  if  gold  be  present  the  ash  will  be  purple  or  brown,  if  much  gold 
be  present,  on  rubbing  the  ash  in  a  mortar  (agate)  it  will  show  the  colour  of 


PLATINUM,     IRIDIUM     AND     MOLYBDENUM  25 

burnished  gold.  Merely  grinding  ores  in  an  agate  mortar  and  washing 
carefully  is  usually  quite  sufficient  to  detect  even  traces  of  gold.  But 
where  it  is  practicable  the  ore  may  be  first  treated  with  HC1  free  from 
Cl,  or  HNO3  free  from  N.  oxides,  to  remove  other  metals ;  remove  silica 
by  HF. 

Platinum.    Pt,  193-3. 

DRY  TEST. — Heat  0*1  gm.  or  less  of  PtCl4  on  char,  or  match,  crush 
in  agate  mortar  and  wash  away  the  char,  powder  :  grey  metallic  Pt.  Insol. 
in  H2SO4,  in  HC1  and  in  HNO3,  but  sol.  in  aq.  regia. 

WET  TESTS. — Dissolve  '05  gm.  H2PtCl6  in  7  c.c.  aq. 

SH2  :  dark  brown  ppt.  of  PtS2,  favoured  by  warming  ;  insol.  in  HC1 
and  HNO8,  but  sol.  in  aq.  regia  and  in  yellow  NH4SH. 

NH4SH  :  PtS2,  as  above. 

NH4C1  and  2  c.c.  alcohol  :  yellow  crystalline  ppt.  of  (NH4)2PtCl6. 

KC1  and  2  c.c.  alcohol  :  yellow  crystalline  ppt.  of  K2PtCl6. 

Zn  :  ppt.  of  metallic  Pt. 

SnCl2  :  brown-red  colour  from  formation  of  PtCl2. 

To  separate  Au  and  Pt  from  solution,  reduce  the  Au  by  H2C2O4,  filter 
off,  and  then  evaporate  with  NH4C1  to  obtain  the  Pt  as  (NH4)2PtCl6. 

Iridium.    Ir,  191*5. 

DRY  TESTS. — i.  Fused  with  KHSO4  it  is  oxidized,  but  not  dissolved. 
(Distinction  from  Rh.)  2.  Heat  a  minute  particle  of  any  Ir  salt  on  char, 
or  porcelain  :  finely-divided  Ir. 

WET  TESTS. — Diss.   '02  gm.   IrCl3  in  5  c.c.  aq. 

SH2  :  the  colour  is  discharged,  S  set  free,  and  a  brown  ppt.  of  iridic 
sulphide  IraSs  forms. 

NH4SH  :  same  as  SH2;  sol.  in  excess. 

KOH  in  excess  :  green  colour,  and  a  dark  [brown  ppt.  of  K2IrCl6 ;  warm 
the  solution  :  red  colour  changing  to  blue  (distinction  from  Pt) ;  evaporate 
to  dryness  with  aq.  :  blue  residue  of  IrO2. 

KC1  :  dark  brown  ppt.  of  K2IrCl6. 

NH4C1,  from  strong  sols.   :  dark  red  crystalline  ppt.  of  (NH4)2IrCl6 

Molybdenum.    Mo,  95-3 

DRY  TESTS. — i.  In  bunsen  flame  :  yellowish  green  colour. 

2.  Blowpipe.     On   char.,  or  match,    in   inner   flame  :  grey  powder  of 
Mo  ;  in  outer  flame  :  yellow  crystalline  incrustation,  white  on  cooling. 

3.  Borax  bead.     In  outer  flame,  yellow ;  in  inner,  dark  brown  bead. 


26  SELENIUM 

4.  Mierocosmic  salt.     Green  bead  in  inner  and  outer  flames. 

WET  TESTS. — Diss.  OT  gm.  (NH4)2MoO4  in  10  c.c.   aq. 

HC1  (or  HN03  or  H2S04)  on  boiling  throws  down  white  MoO3,  sol.  in 
excess  of  acid ;  evaporate  to  dryness  with  H2SO4  :  blue  colour. 

SH-2  (in  acid  sol.)  :  a  blue  colour  and  then  a  brown  ppt.  of  MoS3  ; 
warm  and  pass  SH2  for  some  time  for  complete  precipitation.  Sol.  in 
alkalis  and  alk.  sulphides. 

NH4SH  :  same  as  SH2 ;  sol.  in  excess. 

SnCl2,  or  Zn  and  HC1  :  brown,  green  or  blue  colour  according  to  the 
degree  of  concentration. 

KCNS,  or  zinc  and  HC1  :  crimson  colour,  which  can  be  taken  up  by  ether. 

Na2HP04  (OP  Na3As04)  and  HN08  on  warming  :  yellow  ppt.,  sol.  in  excess 
of  alkalis. 

In  minerals,  e.g.,  Molybdenite  (MoS2),  or  Wulfenite  (PbMoO4),  first  heat 
with  dil.  HC1  to  dissolve  out  Fe  and  Zn,  extract  residue  with  strong 
HC1  and  evaporate  to  dryness.  Digest  with  NH4OH,  filter  and  concentrate, 
when  crystals  of  (NH4).2MoO4  separate,  to  which  the  usual  tests  can  be 
applied. 

Selenium.    Se,  is-s. 

DRY  TESTS — i.  Blowpipe,  (a)  On  char,  in  inner  flame  :  odour  of  decaying 
horse-radish.  Se  burns  with  a  bluish  flame  to  SeO2.  (b)  On  char,  with 
Na2CO3,  in  inner  flame  or  on  match  :  fused  mass  of  Na  selenide,  Na2Se  ; 
this  placed  on  a  silver  coin  and  moistened  yields  a  black  stain,  and  with 
HC1  the  characteristic  odour  of  SeH2. 

2.  Heated  in  a  roasting  tube,  selenides  evolve  a  peculiar  odour  of 
decaying  horse-radish  and  yield  a  red  sublimate  of  Se. 

SELENITES. 

WET  TESTS. — Diss.   'i  gm.  of  Na  selenite  (Na2SeO3)  in  7  c.c.  aq. 

SH2  in  e°ld  acid  sol.  :  yellow  ppt. ;  in  hot  sol.  :  an  orange  ppt. 
(SeS2  ?)  which  soon  decomposes  into  free  S  and  Se,  sol.  in  NH4SH. 

BaCl2,  in  neutral  sols.  :  white  ppt.  of  BaSeO3,  sol.  in  HC1  and  in 
HNO3. 

SnCla  OP  H2S03  (and  2  drops  of  HC1)  :  red  ppt.  of  Se,  which  becomes  grey 
on  heating. 

Cu  and  HC1,  warm  :  ppt.  of  black  Se,  which  after  standing  becomes  red. 

Mg  OP  Zn  in  slightly  acid  sols.  :  red  flakes  of  Se.  Diss.  out  any 
excess  of  Mg  or  Zn  with  HC1 ;  the  Se  is  left  in  the  form  of  the  metallic 
fragments  of  Mg  or  Zn. 


TELLURIUM  27 

KI  :  scarlet  ppt.  of  SeI4.  This  on  heating  quickly  sublimes,  the  sub- 
limate is  hardly  distinguishable  from  that  of  Se  itself. 

Selenates  also  give  the  above  reactions  after  reduction  to  selenites  by 
boiling  with  HC1. 

SELENATES. 

WET  TESTS. — Diss.   *i  gm.  of  K2SeO4  in  3  c.c.  aq. 

HC1  :  no  change ;  boil,  Cl  is  evolved  and  the  selenate  is  reduced  to 
selenite. 

SH2  :  no  ppt.  at  first,  i.e.,  until  the  selenate  has  been  reduced  to  selenite 
by  the  SH2. 

BaCl2  :  a  white  ppt.  of  BaSeO4,  insol.  in  cold  but  sol.  in  hot  HC1,  with 
evolution  of  Cl  and  reduction  to  Ba  selenite. 

Tellurium.    Te,  126. 
DRY  TESTS. — i.  Blowpipe.     On  char.  :  thin  white  incrustation. 

2.  Tellurides,  Tellurites  and  Tellurates  when  fused  with  Na2COs  on  char, 
or  on  match  in  the  inner  flame  :  Na  telluride ;  this  placed  on  a  silver  coin 
and  moistened   produces  a  black   stain,  and  with  HC1  it  yields  black  Te, 
and  TeH2  which  smells  something  like  SH2. 

3.  For  minerals  (Tellurides)  use  KCy  as  well  as  Na2CO3. 

4.  Tellurides  heated  in  a  roasting  tube  :  white  fusible  sublimate  of  TeO2. 
To  extract  from  minerals,  fuse  '2   gm.  with   ten   times  the   weight   of 

KCy  in  a  bent,  hard-glass  tube  through  which  H  is  passed,  K2Te  is 
formed.  Extract  this  with  aq.  :  red  solution  ;  on  passing  a  current  of 
air  through  this,  scales  of  Te  are  precipitated;  heat  on  char.,  a  slight 
odour  is  emitted  and  white  TeO2  is  deposited. 

TELLURITES. 

WET  TESTS. — Diss.   '2  gm.  of  K2TeO3  in  6  c.c.  aq.  or  'i  gm.  Te  in  5 
c.c.  of  strong  HNO3,  and  nearly  neutralize  with  NaOH. 
H20  :  ppt.  of  white  H2TeO3  (from  acid  sols.) 
HC1  :  ppt.  of  white  H2TeO3  (from  the  HNO8  sol.) 
SH2  :  ppt.  of  brovvn  TeS2  in  acid  sols.,  easily  sol.  in  NH4SH. 
H2S03,  SnCl2,  or  Zn  and  HC1  :  ppt.  black  Te ;  insol.  in  KCy. 

TELLURATES. 

WET  TEST. — Diss.  o'i  gm.  K2TeO4  in  2  c.c.  aq. 

HC1  :  no  change :  boil,  Cl  is  evolved  and  the  tellurate  is  reduced  to 
tellurite ;  on  dilution,  H2TeO3  comes  down. 


28  BERYLLIUM    AND    CERIUM 

THE  RARER  METALS  OF  GROUP  III. 
are  thrown  down  by  NH4OH  as  hydroxides  or  acids : — 

Beryllium  hydroxide  Be(OH)2  Zirconium  hydroxide  Zr(OH)4 

Thorium  „  Th(OH)4 

Scandium  hydroxide   Sc(OH)s 

Yttrium              ,,  Y(OH)3               Titanium  hydroxide     H2TiO3 

Ytterbium          ,,  Yb(OH)3              Tantalum           ,,           H3TaO4 

Cerium              ,,  Ce(OH)3              Niobium            ,,           H3NbO4 

lanthanum       , ,  I^a(OH)3 

The  reactions  for  the  salts  of  Scandium,  Yttrium,  and  of  some  of  the 

other  rare  metals  are  omitted  on  account  of  the  difficulty  of  obtaining  them 

in  a  pure  condition. 


Beryllium    (Glucinum.)  Be,  9. 

DRY  TEST.  —  Blowpipe.  On  char,  with  Co22NO3  :  a  grey  mass  ;  not 
distinctive. 

WET  TESTS. — Diss.  o'i  gm.  BeSO4  in  5  c.c.  aq. 

NEUOH,  (NaOH,  KOH  or  NH4SH)  throws  down  flocculent  Be(OH)2,  sol.  in 
KOH,  but  reprecipitated  by  dilution  and  long  boiling;  not  sol.  in  NH4OH, 
but  the  fresh  ppt.  is  slowly  dissolved  by  boiling  with  NH4C1. 

Alk.  carbonates  :  white  ppt.  of  basic  carbonate,  sol.  in  excess,  repre- 
cipitated on  dilution  and  long  boiling,  thus  distinguished  from  Al. 

BaC03  '  white  Be  carbonate. 

To  separate  BeO  from  A1203.  Diss.  in  HC1,  pour  slowly,  with  constant 
stirring,  into  a  hot  cone.  sol.  of  (NH4)2CO3  :  ppt.  of  A1(OH)3;  filter,  neu- 
tralize with  HC1,  boil,  add  NH4OH  :  ppt.  of  Be(OH)2. 


Cerium.    Ce.  139-0. 

DRY  TESTS. — i.  Blowpipe.     On  charcoal  :  reddish  brown  CeO2. 
2.  Borax  bead,  outer  flame  :  red  when  hot,  colourless  when  cold ;  inner 
flame  :  colourless ;  but  CeO2  :  yellow  opaque  bead. 

CEROUS  SALTS. 

WET  TESTS. — Diss.    -05  gm.   CeCl3  in  8  c.c.   of  aq. 

NH4OH  :  white  ppt.  of  the  basic  salt ;  tartaric  acid  prevents  this,  (dis- 
tinction from  Y)  ;  insol.  in  excess,  becomes  yellow  on  exposure. 

NaOH  :  white  gelatinous  ppt.  Ce(OH)3,  somewhat  soluble,  gradually 
oxidizes  and  becomes  yellow  ;  Cl  water,  NaCIO,  etc.,  bring  about  the  same 
change  more  quickly. 


LATHANUM,     DIDYMIUM    AND    ZIRCONIUM  29 

(NH4)2S  :  Ce(OH)3,  cerous  hydroxide,  insol.  in  excess. 

H2C204  :  curdy  white  ppt.  of  Ce.  oxalate,  insol.  in  excess  (distinction 
from  Zr),  difficultly  sol.  in  HC1  (Al  and  Be  oxalates  are  soluble).  Converted 
into  CeO2  on  roasting. 

NaCIO,  or  Am.  persulphate  on  boiling  :  yellow  or  red  ppt. 

Na2C03,  KaCOs  or  (NH4)2C03  :  ppt.  of  Ce^CO,. 

BaC03  :  complete  precipitation  on  standing. 

KHS04  saturated  sol.  :  crystalline  ppt.  of  Ce2(SO4)3,3K2SO4  (distinction 
from  Be  and  Al) ;  insol.  in  a  saturated  sol.  of  K2SO4  (distinction  from  Y 
and  Er). 

CERIC  SALTS. 

The  salts  of  CeO2  are  yellow  and  insoluble,  or  sparingly  sol.  in  aq. 


Lanthanum.     La,  137-9. 

DRY  TEST. — Blowpipe.    I^Oa  undergoes  no  change. 
WET  TESTS. — Diss.   '01  gm.  L,aCl3  in  4  c.c.  aq. 
NH4SH  and  NH4OH  :  ppt.  of  basic  salts;   milky  on  washing. 
NaOH  :  I/a  hydroxide,  L,a(OH)8,  insol.  in  excess  ;  unchanged  by  oxidising 
reagents  (distinction  from  Ce). 

(NH4)2C03  :  white  ppt.,  insol.  in  excess  (distinction  from  Ce). 

Didymium.    (Neodymium  1*2-5  and  Praseodymium  139-4.) 
DRY  TEST. — Blowpipe.     Heated  on  char.  Di  salts  leave  a  grey  residue. 
WET  TESTS. — Diss.   '01  gm.  DiCl3  in  5  c.c.  aq. 

NH4OH  and  NH4SH  :  basic  salt,  insol.  in  NH4OH,  but  somewhat  sol.  in 
NH4C1. 

NaOH  :  pale  rose-coloured  gelatinous  Di(OH)3,  insol.  in  excess. 

Na2C03  :  Di(CO3)3,  insol.  in  excess  (distinction  from  Ce),  but  slightly  sol. 
in  NH4C1. 

BaCOs  :  Di(CO3)3,  slowly  and  incompletely. 

(NH4)2C204  :  ppt.,  slowly  sol.  in  cold  HC1  ;  readily  on  warming. 

Di  sols,  yield  characteristic  absorption  bands  in  the  spectroscope. 

Zirconium.    Zr,  89*9. 

DRY  TESTS. — i.  Blowpipe.      ZrO2  becomes  strongly  luminous;  re-heat 
with  Co2NO3  :  a  dull  violet  colour. 

2.  Bopax  bead,  colourless  ;  somewhat  opaque  when  cold. 
WET  TESTS. — Diss.  .05  gm.  Zr(SO4)2  in  10  c.c.  aq. 


30  THORIUM     AND    TlTANUM 

NH4OH  :  white  flocculent  ppt.  of  Zr(OH)4,  insol.  in  excess  and  in  NaOH. 
(Distinction  from  Al  and  Be). 

NH4SH  :  same  as   NH4OH. 

NaOH  :  same  as  NH4OH,  but  soluble  in  boiling  NH4C1.  (Distinction 
from  Be) 

(NH4)2C03 :  white  flocculent  ppt.  of  basic  carbonate,  sol.  in  excess,  repre- 
cipitated  on  boiling.  (Distinction  from  Al.) 

BaC03  :  no  ppt.  cold,  partly  precipitated  when  boiled. 

H2C204  '.  voluminous  white-  ppt.  of  Zr  oxalate  (distinction  from  Al  and 
Be);  sol.  in  excess  of  (NH4)2C2O4  (distinction  from  Th  and  Ce.) 

Na2S208,  boil  :  ppt.  of  ZrS2O3.     (Distinction  from  Y,  Er  and  Di.) 

K2S04  with  Zr(S04)2  :  ppt.  of  the  double  sulphate  of  Zr  and  K,  insol. 
in  excess  of  K2SO4,  sol.  in  HC1.  (Distinction  from  Al  and  Be.) 

K2S04  is  added  to  hot  Zr(SO4)2  :  the  double  sulphate  is  almost  insol.  in 
H2O  and  HC1.  (Distinction  from  Th  and  Ce.) 


Thorium.    Th,  230-8. 

DRY  TESTS. — i.  Blowpipe.  ThO2  is  infusible;  no  characteristic  colour 
with  Co2NO3. 

2.  Borax  bead  :  colourless. 

WET  TESTS. — Diss.   '2.  gm.  Th2SO4  in  8  c.c.   aq. 

NH4OH  or  NaOH  :  white  gelatinous  Th(OH)4,  insol.  in   excess. 

NH4SH  :  same  as  NH4OH  or  NaOH. 

(NH4)2C03,  Na2C03  OP  K2C03  :  ppt.  of  white  basic  carbonate,  readily  sol.  in 
excess,  but  reprecipitated  from  (NH4)>CO3  at  50°. 

BaC03  :  Th2CO3  without  warming. 

H2C204  :  white  Th2C2O4  (distinction  from  Al  and  Be),  not  sol.  in  excess 
nor  in  dil.  mineral  acids  ;  sol.  in  NH4C2H3O2  acidulated  with  HC2H3O2  (dis- 
tinction from  Y  and  Ce) ;  sol.  in  hot  Am.  oxalate  (distinction  from  Ce). 

HF  :  gelatinous  ThF4,  which  gradually  becomes  granular ;   insol.  in  H2O 
and  HF  (distinction  from  Al,   Be,   Zr,   Zn  and  TiO2). 

Na2S203  :  from  neutral  or  acid  sols,  partially  precipitates  ZrS2O8,  mixed 
with  free  S. 

Titanum.    Ti,  47-7. 

DRY  TESTS. — i.  Blowpipe.     On  char.  :  no  change. 

2.  Miepoeosmie  salt  bead  in  outer  flame  :  yellow  while  hot,  eoloupless 
when  cold ;  in  inner  flame  :  yellow  while  hot,  violet  when  cold.  Add  a 
particle  of  Sn  or  Zn  to  the  bead  and  re-fuse  in  the  reducing  flame  :  brighter 
violet,  or  add  a  particle  of  FeSO4  :  a  blood-red  bead  in  the  inner  flame. 


TANTALUM    AND    URANUM  31 

WET  TESTS. — (a)  Boil  O'l  gm.  Ti02  in  3  c.c.  cone.  H,SO4  or  HC1,  dilute 
with  5  c.c.  aq.  and  filter,  (b)  To  dissolve  the  Ti02  completely,  fuse  T  gm. 
with  KHSO4  on  a  porcelain  lid ;  dissolve  the  yellow  mass  in  cold  water, 
then  add  a  few  drops  of  HC1  to  make  a  clear  solution. 

The  alkalis,  their  sulphides  and  carbonates,  and  BaC03  give  white  floccu- 
lent  ppts.  of  orthotitanic  acid,  H2TiO3,  insol.  in  excess ;  if  precipitated  and 
washed  in  the  cold  it  is  sol.  in  HC1  and  H2SO4 ;  hot  aq.  converts  it  into  the 
insoluble  metatitanic  acid. 

Zn  or  Sn  in  acid  sols.  :  blue  ;  if  dilute  :  a  rose  colour.  The  TiO2  is  re- 
duced to  blue  or  purple  Ti2O3,  this  gradually  oxidizes  to  TiO2  and  loses 
colour. 

Na2S203  on  boiling  completely  precipitates  white  TiO2. 

K4FeCy6  :  dark  brown  ppt.  (the  presence  of  Fe  interferes.) 

Tannie  acid  :  brown  ppt.,  changing  to  orange. 


Tantalum.    Ta,  181.6. 

DRY  TESTS. — i.  Blowpipe.  Ta2O5  becomes  yellow  when  strongly 
ignited,  and  insol.  in  HC1  and  H2SO4. 

2.  Mieroeosmie  salt  bead  :  colourless  in  both  flames. 

WET  TESTS. — Diss.   '02  gm.  KTaO3  in  5  c.c.    aq. 

HC1  :  ppt.  of  Ta.2O5,  sol.  in  excess  of  HC1. 

NH4OH  or  NH4SH  :  a  ppt.  (HTaO8  or  NH4TaO3,HTaO3  ?  ). 

K4FeCy<3  :  white  ppt.  ;  add  NH4OH  :  brown. 

KsFeCyc  :  yellow  ppt. 

Zn  and  HC1  :  no  change  or  a  faint  blue  colour.     (Distinction  from  Nb2O5) 

THE  RARER  METALS  OF  GROUP  IV. 

Thrown  down  by  NH4SH  as  : 

Uranyl  sulphide   (UO3)S 
Indium  sulphide  InS 

Thallious  sulphide  T12S  (also  in  Group  I). 

Vanadium  compounds  are  converted  by  NH4SH  into  soluble  ammonium 
thio-vanadate  from  which  HC1  precipitates  V2S3. 

Uranium.    U,  236-7. 

DRY  TESTS. — Blowpipe.  Borax  and  rnicrocosmic  salt  beads  in  outer 
flame  :  yellow  ;  in  inner  flame  :  green  bead.  Not  reduced  on  char,  with 
Na2CO3. 


32  INDIUM 

In  minerals.  Roast  a  small  quantity  of  the  mineral  and  diss.  in  HNO3, 
evaporate  to  dryness  ;  take  up  with  water,  filter  (or  add  an  excess  of 
Na2CO3  and  boil,  filter  off  the  carbonates  of  Fe,  Ca,.etc.)  and  add  KOH, 
when  the  yellow  U(OH)4  is  thrown  down. 

UR ANGUS  SALTS. 

Uranous  salts  are  green  or  greenish. 

WET  TESTS.  Diss.  0*1  gm.  U(SO4)2  in  5  c.c.  aq.,  or  reduce  *i  gm. 
uranic  nitrate  by  Zn  and  HC1. 

NH4SH  :  black  uranous  sulphide,   US. 

Alkalis  :  brown  gelatinous  uranous  hydroxide  U(OH)4. 

Alk.  carbonates  :  green  uranous  hydroxide,  sol.  in  excess. 

AuCl8,  Ag-NOs  :  ppt.  of  Au  or  Ag. 

Ferric  salts  are  reduced  to  ferrous  salts. 

URANIC  SAI/TS. 

Uranic  salts  are  yellow. 

WET  TESTS. — Diss.  o'i  gm  of  Uranylic  nitrate  UO2(NO8)2  in  10  c.c.  aq. 

NH4OH,    KOH    and  NaOH  :  yellow  ppt.  of  (NH4)2U2O7,  insol.  in  excess. 

NH4SH,  in  neutral  .sols.  :  a  dull  yellow  or  brown  ppt.  of  uranylic  sul- 
phide, UO2S,  precipitation  is  hastened  by  NH4C1,  sol.  in  (NH4)2CO3 ;  sol.  in 
acetic  and  other  acids.  Boiled  with  NH4SH  in  excess  it  changes  to  black 
UO  and  S. 

(NH4)3P04  :  white  ppt. 

H2S  :  no  ppt.  in  acid  sols. 

(NH4)2C03,  Na2C03  and  K2C03  :  yellow  ppt.  of  the  double  carbonates  (e.g. , 
pot.  uranic  carbonate),  readily  sol.  in  excess,  reprecipitated  by  boiling  with 
NaOH,  thus  differing  from  Fe. 

K4FeCy6  in  acid  sols.  :  reddish  brown  ppt.    (Characteristic). 

BaCOs  completely  precipitates  U  in  the  cold ;  hence  it  separates  U  from 
Ni,  Co,  Mn,  Fe"  and  Zn. 

Zn  and  HC1  :  a  green  colour,  no  ppt. 


Indium.    In,  113-1. 

DRY  TESTS. — i.  On  charcoal  :  white  ductile  beads. 

2.  Flame  test  :  bluish  colour ;  its  spectrum  shows  a  bright  blue  and 
pale  violet  line. 

In  minerals.  Extract  with  HC1,  pour  off  the  clear  liquid  after  24  hours 
and  add  a  few  drops  of  dil.  H2SO4  to  the  residue,  wash  thoroughly  with  hot 


GALLIUM    AND    VANADIUM  33 

aq.  ;  add  HNO*  and  a  few  drops  of  H2SO4,  evaporate  nearly  to  dry  ness,  add 
aq.  and  filter.  Add  NH4OH  in  large  excess  to  filtrate,  filter,  wash  ppt.  and 
diss.  in  a  very  little  HC1,  add  excess  of  NaHSO4  and  boil,  when 
2ln2O33$O2,8H2O  separates  out. 

WET  TESTS. — Diss.   *oi  gm.  of  In.23SO4  in  5  c.c.  aq. 

Alkalis  :  ppt.  of  In(OH)3,  white  and  voluminous,  insol.  in  excess. 

Alkaline  carbonates  :  gelatinous  ppt.  of  In23CO3. 

SH  -  :  no  ppt.  except  in  dil.  and  slightly  acid  sols. ,  but  it  is  wholly  pre- 
cipitated in  the  presence  of  acetic  acid  as  yellow  sulphide,  In.2S3,  sol.  in 
boiling  NH4SH,  from  which  the  white  sulphide  separates  on  cooling. 

NH4SH,  tartarie  acid  and  an  excess  of  NH4OH  :  a  white  ppt.  of  In.2S3, 
turned  yellow  by  acetic  acid;  sol.  in  hot  'NH4SH. 

Zinc  and  HC1  :  metallic  In. 


Gallium.    Ga,  69-5. 

Occurs  in  certain  zinc  blendes,   etc.     Best   sought   for  by  aid   of  the 
spectroscope. 


Vanadium.    V,  50-8. 

DRY  TESTS. — Blowpipe.  Borax  bead  in  outer  flame,  colourless  or 
yellow ;  in  inner  flame  green,  hot  and  cold.  If  much  V  be  present  the  bead 
is  brown  hot  and  green  when  cold. 

WET  TESTS. — Diss.  0*1  gm.  of  Na  metavanadate  (NaVO3)  in  7  c.c.  aq. 

NH4SH  in  excess  :  brown  colour ;  acidulate  with  H2SO4  :  brown  ppt.  of 
V3SS,  sol.  in  NH4SH. 

H2S,  H2SO.?  or  H2C204  in  acid  sol.  :  blue  colour  due  to  reduction  of  the  vana- 
dates.  With  H.2S,  S  is  also  separated. 

Zn  and  dil.  H2S04,  warm  :  blue,  changing  to  green  and  lavender. 

NH4C1  cone,  sol.,  or  NH4OH  and  NH4C1  :  white  ppt.  of  (NH4)3VO4.  (Charac- 
teristic). 

H202  in  ether,  shake  with  two  drops  of  HC1  :  red  colour. 

Gallic  acid  :  blue  black  colour,  disappears  with  excess  of  reagent. 

K3FeCy6  :  light  green  ppt. 

In  minerals.  Boil  with  cone.  HNO3,  remove  Pb  by  H2SO4  and  filter, 
wash  ppt.  with  alcohol,  the  filtrate  contains  V2O5  :  confirm  by  Zn  and  HC1. 


34  RUBIDIUM   AND   CESIUM 

THE  RARER  METALS  OF  GROUP  VI. — RUBIDIUM  AND  CESIUM. 
Kubidium.    Rb,  84-8.       Caesium.    Cs,  132. 

DRY  TESTS. — (a)  Both  Rb  and  Cs  salts  impart  a  greyish  colour  to 
the  flame.  (&)  The  spectra  afford  the  best  tests.  Rb  gives  two  character- 
istic lines  in  the  red  and  two  in  the  blue ;  Cs  gives  two  light  blue  lines  to 
the  right  of  the  Sr  $  line. 

WET  TESTS.— Use  sols,  of  RbCL2  and  CsCl,. 

RbCl-2  and  CsCl,  :  ppt.  with  H,PtCl6  and  H.AHA  similar  to  the  Pt  ppts. 

The  Rb2PtCl(;  and  Cs.2PtCl6  are  less  sol.  in  aq.  than  K2PtCl6,  hence  the 
latter  can  be  washed  out  by  boiling  with  successive  small  quantities  of  aq. 


REACTIONS    OF  THE   ACIDS. 


INORGANIC  ACIDS. 

Hydrofluoric  Acid.    HF. 

DRY  TESTS. — Most  fluorides  fuse,  some  give  off  HF  gas,  which  attacks 
glass,  all  do  when  fused  with  KHSO4.  Mix  the  powdered  fluoride  with 
KHSO4  and  heat  strongly  in  a  piece  of  hard  glass  tubing,  wash  and  dry 
the  tube  to  render  the  etching  visible.  [NOTE.  Do  not  inhale  the  gas.] 

WET  TESTS. — Diss.  '05  gm.  of  NaF  or  of  NH4F  in  3  c.c.  aq. 

CaCl-2  :  a  transparent  gelatinous  ppt.  of  CaF.2,  insol.  in  HF. 

H2S04  cone.,  warm  :  HF  is  evolved,  rinse  out  the  tube,  dry  it,  and 
note  the  corrosion  of  the  tube. 

BaCl2  :  white  ppt.  of  BaF-2,  sol.  in  HNO3  and  in  HC1. 

H2S04  and  sand  warmed  with  a  dry  fluoride  :  SiF4,  which  deposits  gela- 
tinous silicic  acid  on  a  moist  rod  lowered  into  the  test  tube. 


Hydrochloric  Acid.    HC1. 

DRY  TESTS. — Blowpipe.  Chlorides  heated  in  a  microcosmic  salt  bead 
with  a  little  CuO  impart  a  vivid  blue  colour  to  the  flame.  Most  chlorides 
fuse  but  some  are  decomposed  on  heating,  e.g.,  AuCl3  and  PtCl4. 

H2S04  (cone.),  warm  :  HC1  gas,  which  turns  blue  litmus  paper  red. 

NOTE. — The  cone.  H2SO4  test  can  usually  be  applied  either  to  the  solid 
salt  or  to  its  sol. 

WET  TESTS. — Diss.  'i  gm.  NaCl  in  5  c.c.  of  aq. 

AgNO;!  :  white  curdy  ppt.  of  AgCl  which  darkens  on  exposure  to  light. 
Insol.  in  HNOi(,  sol.  in  NH4OH,  KCy,  etc.  Fuses  to  a  horny  mass. 

H2S04  and  Mn02,  warm  :  Cl,  which  bleaches  litmus  paper. 

K2Cr207  (about  0*1  gm.  in  powder)  and  2  c.c.  of  H2SO4,  on  warming  with 
a  dry  chloride  evolve  red-brown  vapours  of  chromyl  chloride  (CrO2Cl2)  which 
condense  to  a  dark  red  liquid. 

Hypochlorous  Acid.    HC10. 

DRY  TESTS. — Hypochlorites  when  heated  are  converted  into  chlorides 
and  chlorates.  The  CO2  in  the  air  decomposes  them  with  evolution  of 
chlorine, 

35 


36        CHLORIC    ACID,    PERCHLORIC    ACID    AND    HYDROBROMIC    ACID 

WET  TESTS. — Diss.  ;i  gm.  NaCIO  in  6  c.-c.  of  cold  aq.,  or  pass  Cl  into 
6  c.c.  cold  dil.  NaOH  sol. 

Litmus,    Indigo,    etc.,    are    bleached    by    aqueous    solutions    of  hypo- 
chlorites. 

HC1  (dil.)  :  Cl,  recognised  by  its  odour  and  colour. 

MnSOi  :  is  oxidized  to  brown  MnO2,H.2O. 

NiS04  :  is  oxidized  to  black   Ni(OH)3. 

Pb(C2H302)2  :   white    ppt.    of  PbCL2,    which    gradually    becomes    yellow, 
orange  and  finally  brown,  due  to  its  conversion  into  lead  peroxide. 


Chloric  Acid.    HCl(k 

DRY  TESTS. — i.  On  ignition  alkaline  chlorates  fuse  and  evolve  oxygen, 
or  a  mixture  of  O  and  Cl.  They  deflagrate  on  char.  Diss.  the  residue  in 
aq.,  add  AgNO3  sol.  :  white  ppt.  of  AgCl.  2..  When  rubbed  or  heated  with 
oxidizable  substances,  e.g.,  C,  S,  P,  sulphides,  or  cyanides,  they  explode 
violently,  also  when  H2SO4  is  added  to  such  mixtures,  or  warmed  with  a 
chlorate ;  due  toCJP2. 

H2S04,  cone,  heated  with  a  small  fragment  of  KC1O3  :  sharp  detonation. 
[CAUTION.  Use  only  one  small  fragment  of  KC1O3,  about  "003  gm.  is 
sufficient.] 

HC1  :  Cl  and  C1O2  evolved. 

WET  TESTS. — Diss.  'i  gm.  KC1O3  in  3  c.c.  aq.  All  the  chlorates  are 
soluble. 

AgNO*  :  no  ppt. 

H2S04,  cone.  :  CIO.,  (a  greenish-yellow  gas)  is  evolved  and  the  solution 
becomes  orange  coloured,  on  warming  :  violent  explosion. 

Indigo  (and  2.  drops  of  H2SO4)  becomes  bleached. 


Perchloric  Acid.    HC104. 

Perchlorates  are  more  stable  than  chlorates  ;  they  are  decomposed  by 
hot  cone.  H2S04,  but  not  by  the  cold  acid. 
HC1  or  HNO-?  :  no  action. 


Hydrobromic  Acid.    HBr. 

DRY  TESTS. — -Most  bromides,  like  chlorides  and  iodides,  fuse  without 
decomposition ;  also  when  mixed  with  CuO  and  heated  in  the  inner  flame 
bromides  impart  a  vivid  blue  colour  to  the  flame. 


BROMIC     ACID,     HYDRIODIC     ACID     AND     IODIC     ACID.  37 

Add  H2SO4  to  a  small  crystal  and  warm  :  red  vaps.  of  Br. 
WET  TESTS. — Diss.  o'i  gm.  KBr  in  4  c.c.  aq. 

AgNO*  :  pale  yellow,  curdy  ppt.  of  AgBr,  insol.  in  HNO;1 ;  difficultly  sol. 
in  NH4OH,  readily  in  KCy. 

H2S04  :  HBr,  Br  and  SO*  evolved. 

H2S04  and  MnO-2  warmed  with  a  bromide  :  dense  red  vaps.  of  Br. 

Cl  aq.  :  brown  colour  due  to  the  Br  set  free.     Shake  with  CHC13  or  CS2 : 

brown  sol. 

• 

Bromic  &cid.    HBrO , 

DRY  TESTS.— All  bromates  ar«SJ!lecomposed  on  ignition,    and  like  the 
chlorates  deflagrate  when  mixediajBtth  oxidizable  substances. 
WET  TESTS. — Diss.    '05  gm.^KBrO.-!  in  "2  c.c.  aq. 
AgNOs  :  white  AgBr():1,  this  with  HC1  gives  off  Br. 
H<>S04  :  bromic  acid,  which  brealosVup  into  H2O,  Br  and  O. 

\ 

Hydriodic  Acid.    HI. 

DRY  TESTS. — Most  iodides  on  ignition  give  off  I,  but  the  alkaline 
iodides  and  Agl  do  not. 

WET  TESTS. — Diss.  T  gm.  of  KI  in  9  c.c.  aq.  All  the  iodides  are  sol. 
in  acids  except  Agl. 

Ag-NO;,  :  pale  yellow  Agl,  nearly  insol.  in  NH,OH  and  in  dil.  HNO3. 
Sol.  in  KCy,  KI,  NaCl,  Na2S-O,  and  in  HC1. 

Pb2C2H302  :  yellow  PbI2,  sol.  in  hot  aq.,  redeposited  on  cooling. 

Hg-NOa  :  greenish  ppt.,  Hgl. 

lo  :  yellow  ppt.  of  HgI2  changing  to  scarlet,  sol.  in  KI  and  in  HgCL2. 
i  cone.  :  deep  brown  sol.,   due  to   I  ;    on  warming   yields   purple 
vapours. 

H2S04  and  Mn02  :  purple  vapours  of  iodine. 

Cu2S04  :  grey  Cul.  The  cuprous  sulphate,  Cu2SO4,  can  be  prepared  by 
adding  SO,,  FeSCX,  or  Na2SO.?  to  CuSO,.  Chlorides  and  bromides  do  not 
precipitate  CuSO.,. 

Cl  aq.  (or  Br  aq.,  or  dil.  HC1  and  a  drop  of  KN02  sol.)  and  starch  sol.  :  blue 
colour. 

Cl  aq.  (or  Br  aq.)  and  CS>  or  chloroform  :  purple  solution. 

lodic  Acid.    HIO«. 

DRY  TESTS. — All  iodates  decompose  on  ignition,  some  lose  O  and  are 
converted  into  iodides,  and  others  give  off  both  I  and  O.  They  explode 
when  heated  with  charcoal  and  other  combustible  substances. 


38  SULPHURIC   ACID,    AND   SULPHUROUS   ACID 

WET  TKSTS. — Diss  'i  gm.  of  KIO3  in  5  c.c.  aq.  Only  the  alkali  iodates 
are  sol.  in  water. 

BaCL  :  white  ppt.  of  Ba(IO3)2,  difficultly  sol.  in  dil.  HNO3. 

AgN03  :  white  ppt.  of  AgIO3,  sparingly  sol.  in  dil.  HNO3,  but  readily  in 
NH4OH. 

SH2  :  ppt.  of  S. 

HaSO-i  :  ppt.  of  iodine  and  S. 

KI,  starch  sol.  and  acetic  acid  :  blue  "  iodide  of  starch."  Used  as  a 
test  for  the  presence  of  iodate  in  iodides. 


Sulphuric  Acid.    ILSOi. 

DRY  TESTS. — Blowpipe.  Fuse  the  sulphate  with  pure  Na2CO;,  on  char, 
or  on  a  charred  match,  in  the  reducing  flame  to  convert  the  sulphate  into 
Na2S,  place  the  melt  or  fused  mass  on  a  brightened  coin  and  moisten  ;  a 
brown  or  black  stain  will  be  produced.  All  sulphur  compounds  give 
this  reaction. 

WET  TESTS. — Diss.   'i  gm.  of  Na.2SO4  in  2  c.c.  of  aq. 

BaCl2  :  heavy  white  ppt.  of  BaSO4,  insol.  in  HNO3  and  NH4OH.  Dil. 
solutions  require  to  stand  for  some  time. 

Pb2C2H30;  :  heavy  white  ppt.  (PbSO4)  insol.  in  HNO3,  sol.  in  boiling 
cone.  HC1,  in  KOH,  NH4C2H3O,  and  Na2S2O3. 

Free  H>S04  is  recognised  by  evaporating  it  down  on  a  water  bath  with  a 
little  cane  sugar,  or  fragment  of  filter  paper,  which  chars. 

Insoluble  sulphates  (e.g.,  BaSO4).  Boil  with  pure  Na2CO8,  or  fuse  with 
pure  Na2CO3  on  Pt  foil,  dissolve  the  residue  in  water,  filter  off  the  carbonates 
formed,  and  test  the  filtrate  with  BaCl2  as  above. 


Sulphurous  Acid.     ILSOa. 

DRY  TEST. — On  heating,  some  sulphites  give  off  odour  of  burning 
S,(S02> 

WET  TESTS. — Diss.  '2  gm.  of  Na2SO3  in  6  c.c.  aq. 

BaCl2  :  white  ppt.  of  BaSO3,  soluble  in  strong  HC1 ;  if  the  ppt.  is  not 
entirely  soluble  in  HC1  some  H2SO4  is  present,  filter  off  the  BaSO4  formed 
and  to  the  filtrate  add  Cl  water.  If  a  second  ppt.  of  BaSO4  forms  it  is  due  to 
a  sulphite  which  has  been  oxidised  by  the  Cl  to  a  sulphate.  BaSO3  becomes 
insol.  in  dil.  HNO3  from  the  formation  of  BaSO4. 

HC1  (dil.)  :  SO2  is  evolved. 


THIOSULPHURIC    ACID   AND    HYDROGEN   SULPHIDE  39 

AgNOs  :  white  Ag.2SO3,  sol.  in  excess  of  Na.2SOn  ;  add  a  drop  of  H.SOi 
and  warm  :  metallic  Ag. 

KMnCh  with  a  drop  of  H^SOi  is  reduced  and  decolourised  (very  delicate). 

K.2Cr04  sol.  and  2  drops  HC1  :  green  colour. 

FeCls  :  red  colour  ;  on  boiling  :  ppt.  of  brown  basic  salt.  (Distinction 
from  thio-sulphates.) 


Thiosulphuric  Acid.    ILS-Ck 

Only  known  in  combination. 

Most  thiosulphates  are  sol.  in  water. 

DRY  TESTS. — All  thiosulphates  are  decomposed  on  ignition,  some  fuse 
and  the  S  burns. 

WET  TESTS. — Diss.  "5  gm,  Na2S2O3  in  4  c.c.  aq. 

HC1,  warm  :  SO.2  is  evolved  and  S  deposited. 

AgNOs  :  white  ppt.  of  Ag  thiosulphate  (AgfS»Ot),  which  quickly  passes 
into  black  Ag2S. 

FeCLs  :  violet  colour  which  gradually  fades. 

Zn  and  HC1  :  SH.2  and  ppt.  of  S,  the  nascent  hydrogen  generated  reduces 
the  H,S2O3. 


Hydrogen  Sulphide  (Sulphine).    SH2. 

DRY  TESTS. — i.  Ignition  tube.  Many  metallic  sulphides  heated  in  a 
bulb  tube  evolve  SO-  and  yield  a  sublimate  of  free  S.  AsaSs  and  HgS 
sublime  undecomposed. 

2.  Roasting  tube.     Heated  in  an  open  tube  sulphides  evolve  SO.2. 

3.  On  char,   before  the  blowpipe  :  SO.2,   and  sometimes   the   flame   of 
burning  S. 

WET  TESTS. — Only  the  sulphides  of  the  alkalies  and  of  Sr  and  Ba  are 
soluble  in  aq.  ;  Ca  and  Mg  sulphides  are  sparingly  soluble.  Diss  "i  gm. 
Na.2S  in  3  c.c.  aq.  and  filter  off  the  separated  S. 

HC1  (dil.)  :  SH.2  gas  evolved  from  above  and  from  FeS,  MnS,  and  ZnS  ; 
on  heating  the  sol.  S  separates.  SH2  can  be  recognised  by  its  odour. 

[NOTE.  All  the  sulphides  except  those  of  Ag,  Hg,  Pt,  Au  and  As 
evolve  SH.2  with  strong  HC1]. 

Paper  moistened  with  Pb.  acetate  sol.  is  blackened  by  SH2  gas. 

HNO.i  (strong)  :  converts  Bi.2S3,  CuS,  Ag2S,  PbS,  As.2S3  into  sulphates  and 
free  S.  SnS.2,  Sb>S3  and  As.2S3  are  converted  into  SnO.2,  Sb2O4  and  H3AsO4. 

SbCls  sol.  :  orange  Sb2S3. 


40  NITRIC    ACID    AND    NITROUS    ACID 

Na.  nitroprusside  Na.2FeNOCy>  :  purple  colour  with  even  traces  of 
soluble  sulphides,  no  colour  with  free  SH.2. 

[NOTE.  To  prepare  Na2FeNOCy5,  warm  5  c.c.  of  strong  HNO;(  with 
•5  gm.  of  K3FeCyfi  in  a  test  tube,  dilute  and  neutralize  with  Na.2CO3.] 

Nitric  Acid.     HN(k 

DRY  TKSTS. — On  ignition  most  nitrates  fuse  and  give  off  red  fumes  ; 
they  deflagrate  when  heated  with  oxidizable  substances  such  as  organic 
matter,  charcoal,  sulphides  and  alkaline  cyanides. 

WET  TESTS. — Diss.  '2  gm.    of  NaNOs  in  5  c.c.  aq. 

Cu  foil  and  H2S04,  warm  :  red  fumes  of  NO2, 

FeS04,  add  a  crystal  and  4  drops  cone.  H2S04  :  brown  colouration  around 
the  crystal,  due  to  the  evolution  of  NO  and  its  solution  in  FeSO4. 

H2S04  cone.  '5  c.c.  then  carefully  pour  a  solution  of  FeS04  on  to  the 
top  :  brown  ring. 

Diss.  a  particle  of  Brueine  in  one  drop  of  cone.  H2SO4  on  a  watch  glass, 
add  a  drop  of  NaNO;?  sol.  and  stir  :  deep  red  colour. 

Indigo  and  H2SOi  (cone.)  :  the  blue  colour  changes  to  yellow  (isatin). 

To  detect  free  nitric  acid  in  the  presence  of  a  nitrate,  warm  the 
mixture  on  a  water  bath  with  white  wool  or  silk  or  with  small  pieces  of 
quill  ;  a  yellow  stain  shows  the  presence  of  free  nitric  acid. 

Nitrous    Acid.    HNO. 

DRY  TEST. — On  ignition  nitrites  fuse,  yield  oxides,  and  give  off  N  and 
O.  Mixed  with  oxidizable  bodies  they  deflagrate  like  the  nitrates. 

WET  TESTS. — Diss.  'i  gm.  of  KNO2  in  6  c.c.  aq. 

FeS04  and  H2S04  (cone.)  :  a  brown  colour.     (See  HNO3). 

HgN03  is  reduced  to  metallic  Hg  on  warming. 

Indigo  in  H2SO4  :  yellow  isatin. 

KI  and  starch  solution  and  acetic  acid  :  blue  colour  ;  sensitive  to  i  in  10 
millions.  (See  iodides). 

Sulphanilie  acid  and  napthylamine-  Diss.  equivalent  weights  of  these 
in  H2SO4  and  add  i.c.c.  of  the  mixture  to  i  c.c.  of  the  above  nitrite  sol. 
diluted  to  100  c.c.  :  rose  colour.  It  is  said  to  detect  i  of  HNO2  in  10,000,000 
of  aq. 

Meta-phenylenediamine  hydroehloride  and  HC1  one  drop  :  yellow  to  brown 
(i  in  250,000). 

To  detect  nitrates  in  the  presence  of  nitrites.  Destroy  the  nitrite  by 
boiling  with  urea  and  H2S04,  or  with  NH4C1,  when  the  nitrate  may  be  detected 
by  the  FeSO4,  or  Cu  tests. 


SILICIC,   HYDROFLUOSILIC,   BORIC,   METABORIC  AND  PYROBORIC  ACIDS    4! 

Silicic  Acid,  ILSiCX.      Silica,  Si(k 

DRY  TESTS.  —  Blowpipe.  Infusible;  with  Na2CO3  :  clear  glass.  Sili- 
cates fused  in  microcosmic  bead  :  floating  skeleton  of  SiO2. 

Silica  and  all  silicates  except  those  of  Na  and  K  are  practically  insol.  in 
water. 

WET  TESTS.  —  Fuse  "2  gm  of  SiO2  in  -5  gm.  of  Na2CO3  on  Pt  foil  :  clear 
glass  of  Na2SiO3  ;  diss.  the  result  in  10  c.c.  boiling  aq.,  and  use  it  for  the 
following  experiments. 

HC1  (dil.)  when  neutral  :  ppt.  of  gelatinous  H4SiO4  ;  evaporate  5  c.c.  to 
dryness,  the  dry  product  (SiO2)  is  now  insol.  in  water  and  in  acids. 

AgNOs  :  orange  ppt.  of  Ag2SiO3,  sol.  in  acids  and  NH4OH. 

NH4C1  and  (NH4).2C03  :  ppt.  of  H4SiO4. 

HF  decomposes  most  silicates  ;  pass  the  resulting  SiF4  into  aq.  :  gelatin- 
ous H4SiO4. 

Silicates  which  are  insoluble  in  acids.  Finely  powder  and  fuse  the 
silicate  with  Na2CO3  and  K2CO3  on  Pt  foil  ;  extract  the  Na  and  K  silicates 
with  hot  water,  filter  off  the  metallic  carbonates  ;  acidify  the  filtrate  with 
HC1  and  evaporate  to  dryness,  extract  with  hotaq.,  residue  :  SiO2.  Silica  is 
usually  detected  in  the  examination  for  bases. 


Hydrofluosilicic  Acid  (Fluosilicic  or  Silicofluoric  Acid), 

DRY  TESTS.  —  Silicon*  uorides  on  ignition  :  fluorides  and  SiF4.  Heated 
with  H2SO4,  HF  is  evolved. 

WET  TESTS.  —  Diss.  'i  gm.  of  (NH4)2SiFG  in  4  c.c.  aq.,  or  use  a  solution 
of  the  acid  itself. 

BaCl2  :  crystalline  ppt.  of  BaSiF6.  Hastened  by  adding  an  equal  vol.  of 
alcohol. 

SrCl2  :  no  ppt. 

KC1  :  gelatinous  K2SiF6. 

NH4OH  :  gelatinous  H4SiO4. 

Boric  acid,  H3B(k    Metaboric  Acid,  HB02,    Pyroboric  Aci 

All  the  alkali  borates  are  readily  soluble  in  aq.,  the  others  sparingly  ; 
all  are  soluble  in  acids. 

DRY  TESTS.  —  Blowpipe.  (a)  Many  borates  intumesce  (i.e.,  boil  up) 
when  heated,  and  yield  a  colourless  glass.  (&}  Mixed  with  KHSO4  and 
fused  on  Pt.  wire  :  green  flame,  (c)  For  traces  of  boron  mix  the  substance 
with  KHSO4  and  CaF2,  and  fuse  on  Pt  wire  :  green  colour,  due  to  BF3. 


42  PHOSPHORIC    ACID 

WET  TESTS.— Diss.  'I  gm.  of  borax  (Na2B4O7.ioH2O)  in  6  c.c.  aq. 

H2S04  cone.  :  scales  of  H8BO3  (from  strong  solutions  only). 

Turmeric  paper  dipped  into  the  solution  :  brown  colour. 

Cureumine  (or  turmeric)  and  oxalic  acid.  Dry  on  water  bath  :  magenta 
colour,  on  adding  NaOH  it  changes  to  blue.  If  not  already  free,  set  the 
boric  acid  free  by  two  drops  of  HC1  or  H.2SO4. 

BaCl2  :  white  ppt.  of  BaB2O4  forms  slowly ;  sol.  in  acids. 

AgN03  :  white  (Ag3BO3)  sol.  in  HNO3  and  in  NH4OH,  sol.  becomes  black 
on  boiling. 

H2S04  cone,  orglyeerol,  make  into  a  thin  paste  with  a  borate  and  warm, 
add  to  a  little  spirit  and  ignite  :  green  edged  flame. 


Phosphoric  Acid  (Orthophosphoric  Acid).    ILPCh. 

DRY  TESTS. — Blowpipe.  Normal  metallic  phosphates  are  not  decom- 
posed on  ignition  ;  those  containing  H  lose  H2O  and  are  converted  into  pyro 
and  metaphosphates.  Most  phosphates  are  decomposed  on  fusion  with 
K2CO3  and  Na2CO3,  the  phosphates  of  Ba,  Sr  and  Ca  are  only  partly  decom- 
posed ;  in  the  case  of  A1PO4,  add  SiO2  to  the  fusion  mixture.  Most  dry 
metallic  phosphates,  when  heated  with  Mg  or  Na  in  a  tube,  or  fused  by  the 
blowpipe  with  dry  Na2CO3  on  char.,  or  with  the  match  test,  are  reduced  to 
phosphides,  and  these  emit  phosphine  (PH3)  when  moistened  with  water. 
Phosphates  heated  with  Co2NO3  :  blue  colour. 

On  heating  orthophosphoric  acid  it  loses  water  and  yields  pyrophos- 
phoric  acid,  and  finally  metaphosphoric  acid. 

WET  TESTS. — Diss.  'i  gm.  of  Na2HPO4  in  6  c.c.  aq. 

BaCl2  :  white  ppt.  of  BaHPO4,  sol.  in  HNO3  and  in  HC1,  difficultly  sol. 
in  NH4C1. 

CaCl2  :  white  ppt.  of  Ca3P2O8,  sol.  in  HC2H3O2. 

MgCl2  +  NH4C1  +  NHUOH  :  crystalline  ppt.  of  MgNH4PO4.6H2O,  especially 
on  stirring  or  shaking  ;  insol.  in  NH4OH,  sol.  in  acetic  acid.  (See  arsenic 
acid). 

AgN03  :  yellow  ppt.,  AgBP(X,  sol.  in  HNO3  and  in  NH4OH. 

(NH4)2Mo04  in  HN03  cone,  and  warm  :  yellow  crystalline  ppt.  of  ammonium 
phospho-molybdate,  (MoO3)12(NH4)3PO4.  (?) 

FeCl3  :  yellowish  gelatinous  ppt.  of  FePO4,  somewhat  sol.  in  excess  of 
FeCl3,  sol.  in  HC1.  Arseniates  also  give  a  yellow  ppt.,  hence  if  present  they 
must  be  reduced  by  SO2  and  removed  by  SH2.  (See  also  ' '  phosphates ' ' 
table.) 


PYROPHOSPHORIC    ACID,    ETC  43 

Pyrophosphoric  Acid  (ILPaOT)  and  Metaphosphoric  Acid  (HPOs). 

Both  give  white  ppts.  with  AgNO3,  metaphosphates  (with  acetic  acid)  co- 
agulate "albumen,  pyrophosphates  do  not. 

They  do  not  give  ppts.  with  (NH^MoCX  in  the  cold,  but  on  boiling 
they  are  converted  into  orthophosphoric  acid,  which  gives  a  ppt. 

[NOTE.  —  Pyrophosphates  and  metaphosphates  are  converted  into  ortho- 
phosphates  during  the  process  of  analysis,  hence  they  must  be  sought  for  by 
special  methods.] 

Phosphorous  Acid.  ILPCk 

DRY  TESTS.  —  Phosphites  decompose  and  ignite  when  heated  on  Pt. 
foil.  Heated  in  a  tube  they  evolve  H  and  PH3,  and  are  converted  into 
phosphates.  Phosphites  of  the  alkalies  are  soluble  in  water. 

WET  TESTS.  —  Diss.    T   gm.  Na2HPO3  in  4  c.c.   aq. 

AgNOs  :  metallic  silver  ;  the  reduction  is  aided  by  NH4OH  and  warming. 

HgCh  :  HgCl  and  Hg. 

Zn  and  HC1  :  H  and  PH3,  the  gas  burns  with  a  green  colour  and  blackens 
filter  paper  moistened  with  AgNOs,  due  to  the  formation  of  Ag3P  and 
metallic  Ag. 

SO-2  is  reduced  to  S,  and  SH2  is  evolved.  The  phosphite  is  oxidized  to 
phosphate. 

Hypophosphorous  Acid.   H«P02 

DRY  TEST.  —  On  ignition  hypophosphites  evolve  PH8,  and  are  con- 
verted into  pyrophosphates,  M'4P2O7. 

WET  TESTS.  —  Diss.    'i  gm.   NaH2PO2  in  5  c.c.   of  aq. 
H2S04  is  reduced  to  H2SO3  and  S  (on  warming). 
AuCls,  AgN03  and  CuS04  are  reduced  to  metals. 


- 
Zn  and  H2S04  :  H  and  PH3>  with  garlic  odour. 


v^r 
Carbonic  Acid.  ILCOs. 


DRY  TESTS.  —  On  ignition,  alkali  carbonates  fuse  without  decomposition, 
at  high  temperatures  they  volatilize  ;  the  others  decompose  into  CO*  and 
oxide  of  the  metal,  or  CO2,  O  and  the  metal. 

WET  TESTS.  —  Diss.   'i  gm.   Na2CO3  in  5  c.c.  aq. 

HC1  :  effervescence,  a  rod  or  tube  which  has  been  dipped  into  lime  water 
and  lowered  into  the  escaping  gas  becomes  coated  with  CaCO3  ;  the  gas 
extinguishes  a  taper.  Native  MgCO3,  CaMg(CO8)2  and  FeCO8  are  very 
slowly  decomposed  by  cold  HC1. 

BaCl2  :  white  ppt.  of  BaCO3  which  dissolves  in  dil.  HC1  with  effer- 
vescence. 


44  HYDROCYANIC  AND  CYANIC  ACIDS 

ORGANIC   ACIDS. 

Hydrocyanic  Acid.  HCN  or  HCy. 

DRY  TESTS. — Blowpipe.  (a)  KCy  and  NaCy  fuse  when  heated  and 
gradually  oxidize  to  cyanates  (M'CNO)  ;  cyanides  of  the  heavy  metals  are 
decomposed  and  cyanides  of  Au,  Hg,  Ag,  etc.,  yield  free  cyanogen  (CN)a  or 
Cy2  and  brown  paracyanogen  Cyn ;  Na,  K,  Hg  and  Ba  cyanides  are  sol.  in 
aq.,  those  of  Ag,  Cd,  Co,  Cu,  Ni  and  Zn  are  not.  (d)  Fuse  with  a  particle 
of  Na2S2Os  in  a  Pt  ring  until  the  S  flame  appears,  place  the  bead  in  a  sol.  of 
Fed*  :  a  red  colour  of  Fe(CyS)8.  (c)  Fuse  a  cyanide  with  KOH  :  NH3. 

WET  TESTS. — Diss.   'i   gm.   KCy  in  6  c.c.   aq. 

The  cyanides  of  the  alkalies  emit  the  odour  of  HCy,  from  the  action  of 
CO2  and  H2O  in  the  air. 

HC1  (dil.)  :  HCy.    Do  not  inhale,  as  HCy  is  intensely  poisonous.    Test  the 
odour  with  great  care  by  wafting  the  fumes  towards  the  nose  with  the  hand. 
Certain   double   cyanides   also    evolve    HCy,  e.g.,  KCy,  AgCy  -\-    HNO3  = 
AgCy  +  HCy  +  KNO3  ;  but  other  double  cyanides  do  not,  e.g., 
K4FeCy6  -f  4HC1  =  H4FeCyfi  (Ferrocyanic  acid)  +  4KC1. 
2K3FeCy6  +  6HC1  =  2H3FeCy6  (Ferricyanic  acid)  +  6KC1. 
2K«CoCy6  +  6HC1  =  2H3CoCy6  (Cobalticyanic  acid)  +  6KC1. 

Ag-N03  :  white  curdy  ppt.  of  AgCy,  insol.  in  dil.  HNO3 ;  sol.  in  NH4OH, 
Na2S.2O3  and  in  excess  of  KCy.  On  ignition  :  metallic  Ag  (AgCl  fuses).  If 
AgCy  and  AgCl  are  both  present,  wash,  ignite,  dissolve  out  the  metallic  Ag 
by  HNO3,  and  add  HC1  :  ppt.  of  AgCl.  Add  dil.  H2S04  to  a  cyanide  in  a  watch 
glass  and  invert  over  it  another  watch  glass  moistened  inside  with  yellow 
NH4SH,  in  a  few  minutes  NH4CNS  is  formed,  evaporate  this  nearly  to  dry- 
ness  over  a  water  bath  and  add  a  drop  of  FeCl3  sol.  :  a  blood  red  colour. 

HgN03  :  grey  ppt.  of  Hg. 

FeS04,  FeCl3  and  HC1,  on  warming  :  ppt.  of  Prussian  blue. 

NaN02  and  FeCl3  and  dil.  H2S04  until  the  colour  is  yellow ;  warm  gently, 
cool,  add  NH4OH  and  filter,  then  one  drop  NH4SH  :  violet  colour  ;  due  to 
Na  nitroprusside. 

Cyanic  Acid  (Carbimide).  HCyO. 

Pot.  cyanate,  KCNO,  is  formed  by  the  oxidation  of  KCy.  KCyO 
deliquesces  and  smells  of  NH3. 

KCNO  -f  2H2O  =  KHCO3  +  NH8. 

The  cyanates  of  the  alkalis,  alk.  earths  and  some  others  are  sol.  in  aq.,  the 
solutions  decompose  and  evolve  NH3.  On  warming  the  sol.  of  Am.  cyanate 
it  changes  into  urea,  NH4CyO  :  (NH2)3CO. 


HYDROFERROCYANIC  AND  HYDROFERRICYANIC    ACIDS  45 

DRY  TESTS. — On  ignition,  many  of  the  cyanates  of  the  heavy  metals 
evolve  CO2  and  form  cyanides. 

WET  TESTS. — Diss.   '05  gm.  KCyO  in  2  c.c.  aq. 

HC1  :  pungent  odour  of  HCyO,  irritates  the  eyes. 

AgNOs  :  white  ppt.,  AgCyO,  sol  in  NH4OH  and  in  dil.  HNO3. 

Hydroferrocyanic  Acid.  ILFeCeNe  or  H4FeCy6. 

DRY  TESTS. — On  strong  ignition  some  fuse  and  yield  N,  M'Cy,  Fe,  iron 
carbide,  and  some  M'CyO ;  thus  K4FeCy6  :  4KCy  +  2C  +  Fe  -f  N2.  The 
alk.  ferrocyanides  are  sol.  in  aq.,  those  of  Ba,  Sr,  and  Ca,  sparingly  sol.  ; 
most  of  the  others  are  insol.  in  aq.,  and  some  are  insol.  in  acids. 

WET  TESTS. — Diss.  'i  gm  of  crystallized  K4FeCy6  in  7  c.c.  aq. 

H2S04  (cone.)  :  CO  evolved. 

H2S04  (dil.)  :  HCy  evolved. 

HC1  (cone.)  :  white  ppt.  of  H4FeCy6,  changes  to  blue. 

Ag-NOs  :  white  ppt.  Ag4FeCy6  sol.  in  KCy  but  insol.  in  dil.  HNO3  and  in 
NH4OH. 

CuS04,  in  excess  :  chocolate  ppt.  of  Cu2FeCy6. 

FeS04  :  pale  blue  ppt.  of  pot.  ferrous  ferrocyanide  K2Fe(FeCy6)  which 
rapidly  oxidizes  to  ferric  ferrocyanide  (Prussian  blue)  Fe4(FeCy6)3. 

FeCl3  :  Prussian  blue,  insol.  in  dil.  mineral  acids,  but  sol.  in  oxalic 
acid  (  :  blue  ink)  and  ammonium  tartrate  (  :  violet-  ink).  [NoTE.  This  is 
also  a  test  for  tartrates.]  If  insufficient  FeCl8  is  added  this  ppt.  is  sol.  in  aq., 
known  as  soluble  Prussian  blue,  also  used  as  a  blue  ink.  Prussian  blue  is 
decomposed  by  alkalis. 

Fe4(FeCy6)3  +  I2KOH  =  3K4FeCy6  +  4Fe(OH)3 
i.e.,  the  cathion  iron  is  precipitated  but  not  that  in  the  anion. 

Hydroferricyanic  Acid.     H3Fe(CN)6  or  H3FeCy6. 

Ferricyanides  can  be  obtained  by  oxidising  ferrocyanides  with  Cl,  etc. 

DRY  TESTS. — On  heating,  K3FeCy6  evolves  N  and  Cy,  and  leaves  a 
residue  of  paracyanogen,  carbon,  iron  carbide  and  Prussian  blue.  The 
alkali  ferricyanides  are  sol.  in  water,  most  of  the  others  are  not. 

WET  TESTS. — Diss.  0*1  gm.  of  K3FeCy6  in  3  c.c  .aq.,  or  add  Cl  water 
to  3  c.c.  K4FeCy6  solution. 

AgN03  :  reddish  ppt.  of  Ag3FeCy6,  sol.  in  NH4OH  and  in  KCy,  insol.  in 
dil.  HNO3. 

FeS04  :  blue  ppt.  of  ferrous  ferricyanide,  Fes(FeCy6)2  (Turnbull's  blue), 
decomposed  by  KOH. 

FeCls  '•  brown  or  green  colour. 


46  THIOCYANIC,    FORMIC    AND    ACETIC    ACIDS 

Thiocyanic  Acid  (Sulphocyanic  Acid).       HCNS  or  HCyS. 

DRY  TESTS. — KCyS  on  ignition  is  converted  into  KCyO,  K.2SO4  and 
SOa.  The  thiocyanates  of  the  heavy  metals  evolve  CS2,  N  and  CN,  and 
leave  a  metallic  sulphide. 

WET  TESTS. — Dissolve  "01  gm.  NH4C)TS  or  KCyS  in  3  c.c.  aq. 

Ag-N03  :  white  curdy  ppt.  of  AgCyS,  sol.  in  NH4OH,  but  insol.  in  dil. 
acids. 

CuS04  (2  drops)  :  black  ppt.  of  Cu(CyS)2.  If  the  CuSO4  is  in  excess  there 
is  no  ppt. 

FeCl3  :  blood  red  coloured  sol.  of  Fe(CyS)3,  on  adding  Zn  to  the  red  sol. 
SH2  is  evolved.  HgCla  discharges  this  colour,  HC1  does  not. 

Formic  Acid.     H.COOH. 

Fuming  liquid,  with  pungent  odour,  boils  99°  C.,  mixes  with  H2O, 
alcohol,  and  ether. 

Its  salts  are  readily  sol.,  except  Pb  formate;  the  salts  (and  the  free  acid) 
are  strong  reducing  agents. 

DRY  TESTS. — Solid  formates  when  heated  char  slightly,  and  evolve 
CO  and  CO2. 

WET  TESTS. — Diss.  'oi  gm.  Na  formate,  NaCHO2,  in  7  c.c.  aq. 

H2S04,  dil.  :  formic  aoid  is  evolved,  recognised  by  its  odour  and  by  its 
blackening  paper  moistened  with  AgNO3. 

H2S04  cone,  decomposes  formic  acid  and  the  formates,  and  CO  is  evolved. 

H2S04  and  alcohol  :  formic  ether  (odour  of  rum). 

AgN03,  warm  :  black  ppt.  of  Ag. 

HgCl2,  warm  :  white  ppt.  of  HgCl  or  of  grey  metallic  Hg. 

FeCls  :  red  colour  (like  acetates)  destroyed  by  the  addition  of  HC1  ;  on 
boiling,  basic  ferric  formate  is  precipitated  and  the  liquid  becomes  colourless. 

KMn04  sol.,  is  reduced  by  formic  acid. 

Acetic  Acid.    CIL.COOH. 

A  colourless  pungent  acid  liquid,  crystallizes  at  i6'5°  and  boils  at  118°, 
its  vapour  burns  with  a  bluish  flame.  Mixes  with  water,  alcohol,  and  ether 
in  all  proportions. 

DRY  TESTS. — Acetates  on  ignition  give  off  acetone  and  other  inflam- 
mable vapours  and  leave  a  carbonate,  oxide,  or  metal. 

Dry  acetates  heated  with  a  little  As2O3  (use  *oi  gm.),  give  off  Cacodyl 
As(CH3)2  (or  cacodyl  oxide,  (CH3As)2O),  recognised  by  its  offensive  odour. 
[N.B. — This  is  extremely  poisonous.  Caution. — Never  apply  the  test  tube  to 


PROPIONIC,    BUTYRIC    AND    OXALIC    ACIDS  47 

the  nose  when  testing  by  odour,  always  waft  the  vapour  from  the  test  tube 
towards  the  nose  by  the  hand,  or  cover  the  mouth  of  the  test  tube  with  a 
piece  of  filter  paper,  remove  the  paper  after  a  few  moments  and  ascertain 
whether  it  has  acquired  any  odour]. 

WET  TESTS.      Diss.   '2  gm.  Na  acetate  (NaC2H3O2)  in  4  c.c.  aq. 

H2S04  (either  dil.  or  cone.)  :  odour  of  "  vinegar,"  i.e.,  of  acetic  acid. 

H2S04  and  alcohol  on  warming  :  ethereal  odour  of  ethyl  acetate. 

AgN03,  in  strong  solutions  :  white  crystalline  Ag  acetate ;  not  reduced 
on  boiling.  (Distinction  from  formic  acid.) 

FeCls  in  neutral  sols.  :  dark  red  colour,  destroyed  by  HC1  ;  on  boiling  a 
ppt.  of  basic  ferric  acetate  forms  and  the  solution  becomes  colourless. 

Propionic  Acid.    C2H5.COOH. 

Has  the  odour  of  rancid  butter  and  of  acetic  acid.  Occurs  in  sour  cocoanut 
milk,  oil  of  amber,  and  in  certain  wines  when  the  fermentation  has  gone  too 
far.  Propionates  are  sol.  in  aq.  If  the  free  acids  (formic,  acetic,  and  pro- 
pionic)  are  evaporated  to  dryness  with  PbO  and  extracted  with  cold  aq.  and 
filtered,  the  Pb  acetate  and  Pb  formate  will  be  found  in  the  residue  and  the 
Pb  propionate  (basic)  in  the  solution. 

Butyric  Acids.    C3H7.COOH. 

The  normal  acid,  C3H7.COOH,  has  a  strong  and  characteristic  odour  ;  b.p. 
163°  C.  The  iso-butyric  acid  (CH3).2CH.COOH,  boils  at  150°,  otherwise  it 
closely  resembles  the  former.  Both  are  sparingly  sol.  in  water.  Can  be 
separated  from  aqueous  solution  by  agitating  with  ether  and  then 
evaporating. 

All  the  butyrates  are  sol.  in  H2O. 

WET  REACTIONS. — Diss.    'i   gm.  of  Na  butyrate  in  6  c.c.  aq. 

H2S04,  warm  :  odour  of  butyric  acid. 

H2S04  and  alcohol  :  ethyl  butyrate,  C2H5.C4H7O2,  odour  of  pine  apples 
(best  test). 

AgNOs  :  white  ppt.  of  AgC4H7O2. 

FeCl3  :  reddish  brown  sol. 

Cu  acetate,  with  strong  solutions  :  bluish-green  oblique  crystals. 

Pb  acetate  :  white  ppt.,  becoming  oily  on  warming. 

Oxalic  Acid.    (COOH)2. 

Crystallizes  in  rhombic  prisms  (COOH)2.2H2O,  which  lose  HaO  and 
effloresce.  Intensely  poisonous.  The  normal  oxalates  of  the  alkalis  are  sol. 
in  aq. ,  most  of  the  others  are  not. 


48  TARTARIC    ACID 

DRY  TESTS. — On  heating  in  a  tube  it  yields  aq.  and  sublimes,  part  is 
decomposed  into  CO,  CO2  and  formic  acid. 

On  ignition  alk.  oxalates  give  off  CO,  blacken  slightly  and  leave  a  car- 
bonate; oxalates  of  the  alk.  earths  give  off  CO  and  CO2,  and  leave  a 
carbonate  which  at  high  temps,  is  converted  into  M"O. 

H2S04  (cone.),  warm,  oxalic  acid  and  oxalates  decompose  into  CO  and  CO2 
without  blackening.  Test  for  CO2  by  CaO2H2  on  the  end  of  a  glass  rod. 

WET  TESTS. — Diss.   '2  gm.  of  (NH4)2C2O4  in  4  c.c.  aq. 

CaCl2  :  white  ppt  of  CaC2O4,  sol.  in  HC1  or  HNO3,  almost  insol.  in  KOH, 
NH4OH,  oxalic  and  acetic  acids. 

SpCl2,  with  neutral  oxalates  :  a  white  ppt.  of  SrC2O4,  insol.  in  acetic  acid 
and  in  boiling  aq.  (Distinction  from  tartaric  and  citric  acids.) 

AgN08  :  white  ppt.  of  Ag2C2O4,  sol.  in  dil.  HNO3  and  NH4OH. 

KMn04  (add  H2S04)  is  reduced  and  decolourized  on  warming.  N.B. — Use 
a  very  weak  sol.  of  KMnO4. 


Tartaric  Acid.    (CH.OH)2(COOH)2. 

Large  colourless  crystals,  very  sol.  in  aq.,  sol.  in  alcohol.  The  normal 
salts  of  the  alkalis  are  readily  sol.  in  aq.,  but  the  acid  salts  of  K  and  NH4  are 
only  slightly  soluble. 

DRY  TESTS. — On  heating,  tartaric  acid  and  tartrates  evolve  odour  of 
caramel ;  the  tartrates  of  the  alkalis  and  alk.  earths  leave  a  carbonate  mixed 
with  carbon,  the  tartrates  of  the  heavier  metals  leave  the  metal  or  its  oxide 
mixed  with  carbon. 

H2S04  (cone.),  warm,  blackens,  with  evolution  of  CO,  CO2,  and  SO2. 

WET  TESTS. — Diss.  '5  gm.  tartaric  acid  in  5  c.c.  aq. 

KC1,  stir  and  let  stand  for  some  time  :  crystalline  ppt.  of  KHC4H4O6  with 
an  acid  tartrate  or  free  tartaric  acid,  but  boric  acid  prevents  the  precipitation  ; 
insol.  in  acetic  acid,  readily  sol.  in  HC1,  HNO3,  H2SO4,  alkalis  and  alk. 
carbonates. 

Ca02H2  (in  excess)  with  free  tartaric  acid  :  white  ppt.  of  Ca  tartrate,  sol. 
in  NaOH  and  acetic  acid. 

FOR  NEUTRAL  TARTRATES. — Diss.  '5  gm.  NH4KC4H4O6  in  5  c.c.  aq. 

CaCl2,  with  neutral  sols,  of  tartrates  :  white  ppt.  of  CaC4H4O6,  stir  and  let 
stand ;  sol.  in  free  tartaric  acid. 

AgN03  :  white  curdy  ppt.  of  Ag2C4H4O6,  sol.  in  excess  of  the  tartrate,  in 
NH4OH  and  in  HNO3. 

Partially  dissolve  some  of  the  Ag2C4H4O6  ppt.  in  dil.  NH4OH,  add  a 
fragment  of  AgNOn,  immerse  the  test  tube  in  a  beaker  of  warm  water  (about 


SUCCINIC     ACID     AND     MAUC    ACID  49 

60°  C)  for  10  to  20  minutes;  the  Ag  is  reduced  and  forms  a  mirror  on  the 
test  tube.  A  little  free  NaOH  is  said  to  hasten  the  formation  of  the  mirror. 
N.B. — Clean  the  test  tube  before  using  with  NaOH  and  distilled  aq. 


TO   DISTINGUISH    BETWEEN   CITRIC   AND   TARTARIC   ACIDS. 

Resorein  and  about  2  c.c.  cone.  H2SO4  added  to  a  very  small  quantity  of 
a  solid  tartrate  or  tartaric  acid,  and  carefully  warmed  :  bright  red  colour. 

Pyrogallol,  instead  of  resorcin  :  purple. 

FeS04,  a  few  drops  of  H202  and  an  excess  of  NaOH  :  blue  to  purple 
colour.  Citric  acid  does  not  give  the  above  colour  reactions. 


Succinic  Acid,     C2H4(COOH)2. 

Crystallized;  readily  sol.  in  water,  alcohol,  and  ether,  insol.  in  chloro- 
form. Benzoic  acid  is  soluble. 

DRY  TESTS. — When  heated  in  a  tube  it  yields  water  and  the  anhydride 
sublimes,  emits  irritating  vapours  and  causes  coughing. 

Solid  succinates  when  warmed  with  KHSO4  yield  succinic  acid  in  oily 
drops,  which  crystallize  on  cooling. 

WET  TESTS. — Diss.  '05  gm.  of  ammonium  succinate  in  3  c.c.  aq. 

BaCl2  :  ppt.  of  Ba  succinate  on  stirring.  Add  alcohol  if  the  solution 
be  dilute.  Benzoates  do  not  yield  a  ppt.  with  BaCl2. 

FeCl3  :  pale  brownish  ppt.  of  basic  ferric  succinate,  sol.  in  acids. 

Pb(C2H302)2  ;  white  amorphous  ppt. ,  sol.  in  excess  of  either  the  succinate 
or  Pb  acetate ;  Pb  succinate  crystallizes  out  on  standing. 


Malic  Acid.    C,Ha(OH)(COOH)2. 

Crystallized  ;  readily  sol.  in  aq.  and  in  alcohol. 

DRY  TESTS. — Heated  in  a  tube  it  yields  aq.  and  a  crystalline  sublimate 
of  maleic  and  fumaric  acids;  at  higher  temperatures  it  emits  odour  of 
caramel,  chars  and  evolves  CO  and  CO2. 

WET  TESTS. — Diss.   "05  gm.  of  Na  malate  in  3  c.c.  aq. 

CaCl2  :  white  ppt.  of  CaCJr^O.^HsO,  on  boiling  or  adding  2  vols. 
alcohol. 

Pb  acetate  :  a  white  ppt. ,  which  fuses  on  warming  the  liquid. 

AgNOa  :  a  white  ppt.,  becoming  grey  on  boiling. 


50  CITRIC    ACID,     LACTIC    ACID    AND    BENZOIC    ACID 

Citric  Acid.    CsIUOHXCOOH).,. 

Crystallized  ;   readily  sol.  in  aq.  and  in  alcohol. 

DRY  REACTIONS. — On  heating  in  a  tube  citric  acid  yields  aq.  of  crystal- 
lization, fuses  and  gives  off  irritating  fumes  (aconitic  and  citraconic  acids  and 
anhydrides)  and  leaves  a  residue  of  carbon.  Citrates  of  the  alkalis  and  alk. 
earths  leave  a  carbonate. 

WKT  TESTS.— Diss.   -5  gm.  NagCoH-A  in  5  c.c.  aq. 

Ca02H2  :  a  white  ppt.  of  Ca  citrate,  on  boiling  or  long  standing.  (Differ- 
ence between  citric  and  tartaric  acids). 

CaCl2  :  a  white  ppt.  on  long  standing  or  boiling,  in  neutral  or  alk.  sols.  ; 
insol.  in  NaOH,  but  sol.  in  NH4  salts  and  in  acids. 

AgN03  :  white  ppt.  of  Ag3C6H6O7,  sol.  in  NH4OH,  the  sol.  on  boiling  is 
reduced  to  metallic  Ag  (grey  or  black)  but  does  not  form  a  mirror.  (See 
tartaric  acid.) 

H2S04  (cone.)  on  warming,  CO  and  CO2  are  evolved  ;  on  boiling,  the  sol. 
slowly  darkens  and  SO2  is  evolved. 


Lactic  Acids. 

(a)  Fermentation  or  ordinary  laetie  aeid,    CH3.CH.OH.COOH.,    optic- 
ally active. 

(b)  Sareo-laetie,  optically  inactive. 

(c)  Ethene-laetie  aeid  :  CH2OH.CH2.COOH. 

All  three  are  syrupy  inodorous  liquids ;  sol.  in  aq.,  alcohol  and  ether. 
DRY  TESTS. — At   150°,   a  and  b  lactic  acids  lose  water  and   emit  irri- 
tating vapours  of  the  anhydrides. 

WET  TESTS. — Diss.  '2  gm.  Na  lactate  in  5  c.c.  aq. 

H-SOi  (dil.)  warm  :  acetaldehyde  and  formic  acid. 

H2S04  (cone.)  :  CO  evolved. 

Fehling's  solution  :  not  reduced. 

Ca8(P04)2  (if  recently  precipitated)  is  dissolved  by  lactic  acid. 

AgN08  is  reduced  by  boiling  with  lactic  acid. 


AROMATIC    SERIES. 

Benzoic  Acid,  C«H5.COOH. 

Crystallized  in  needles  or  plates,  slight  aromatic  odour.  Sparingly  sol. 
in  cold  aq.,  more  sol.  in  hot,  readily  in  alcohol,  ether,  chloroform,  alkalis, 
etc.  Most  benzoates  are  sol.  in  aq. 


SAUCYUC    ACID    AND    GAWJC    ACID  51 

DRY  TESTS. — Melts  at  121*4°  C.,  volatilizes  with  irritating  fumes. 
Yields  sublimate  of  feathery  crystals  ;  burns  with  smoky  flame.  Benzoic 
acid  and  solid  benzoates  heated  with  CaO  yield  benzene,  C6H6. 

WET  TESTS. — Diss.   "05  gm.  Na  benzoate  in  5  c.c.  aq. 

H2S04  :  ppt.  of  white  crystals  (ben zoic  acid). 

H2S04  and  alcohol,  aromatic  odour  of  benzoic  ether,  C2H5.C7H5O2. 

FeCl3,  in  neutral  sols.  :  buff  ppt.  of  basic  ferric  benzoate,  sol.  in  NH4OH. 

Pb  acetate  :  flocculent  ppt.  of  Pb(C7H5O2)2.H2O,  from  fairly  strong  sols., 
sol.  in  Pb.  acetate  and  in  acetic  acid. 

H2S04  and  a  fragment  of  Mg  :  odour  of  benzaldehyde,  C6H5.CHO. 


Salicylic  Acid.   CeELOH.COOH. 

Crystallized  ;  slightly  sol.  in  cold,  more  sol.  in  hot  aq.,  sol.  in  alcohol, 
ether  and  alkalis. 

DRY  TESTS. — Melts   155°  C. ;    sublimes  at   higher    temps.,    giving  off 
phenol  and  CO2.     Distilled  with  CaO  it  yields  phenol. 

WET  TESTS. — Diss.  "05  gm.  of  Na  salicylate  in  8  c.c.  of  aq. 

H2S04  (dil.)  :  crystalline  ppt.  of  salicylic  acid. 

H2S04  and  methyl  alcohol,  warm  :  odour  of  oil  of  winter   green   (methyl 
salicylate). 

H2S04  (cone.)  containing  a  few  drops  of  6  per  cent.  sol.  of  KN02  yields  on 
warming  a  permanent  red  colour  (phenol  :  a  fleeting  red). 

NaN02,  two  drops  ;  acetic  acid,  four  drops,  and  two  drops  of  a  dil.  sol.  of 
CuS04,  boil  :  intense  red  colour. 

AgN03  :  white  ppt.  of  Ag  salicylate  (but  not  with  the  free  acid). 

HgN03  and  HN03  (Millon's  reagent),  boil  :  red  colour. 

FeCls  :  violet  colour,  destroyed   by   alkalis   and   by   mineral  acids,    not 
destroyed  by  acetic  acid.     (Distinction  from  phenol.) 

Br  water  :  white  cryst.  ppt.  of  tribromo-salicylic  acid. 


Gallic  Acid.    C6H2(OH)3.COOH. 

Yellowish  acicular  crystals  ;  astringent  taste ;  readily  sol.  in  hot  aq. , 
sol.  in  alcohol,  but  sparingly  in  ether. 

DRY  TESTS. — On  heating,  it  melts,  CO2  is  evolved  and  pyrogallol 
sublimes. 

H2S04  (cone.),  heat  for  two  or  three  minutes  :  green  sol.,  changing  to 
claret  or  purple. 

WET  TESTS. — Boil  '02  gm.  with  10  c.c.  aq. 


52  TANNIC    ACID    AND     PYROGAUJC     ACID 

KOH,  one  drop,  warm  :  bright  green,  changed  to  red  by  acids. 
CaCUSa  :  white  ppt.  changing  through  blue,  green  and  violet  to  purple. 
FeSO*  :  pale  blue  colour. 

FeCls  (dil.)  :  dark  blue  ppt.,  sol.  in  excess  to  a  green  solution. 
Gelatin  solution  '•  no  ppt. 

It   is  distinguished  from  tannin  by  not  being  pptd.   from  aqueous  sol. 
by  acids,  by  cinchonine  sulphate  or  by  gelatine. 

KCy  :  crimson,  fleeting,  but  reappears  on  shaking. 
Pb2NOs  :  no  ppt.,  compare  tannic  acid. 
Fehling's  solution  :  slowly  reduced  on  boiling. 


Tannic  Acid  (Digallic  Acid,  Gallotannic  Acid,  Tannin).    CuHio09. 

A  buff  or  colourless  powder,  astringent  taste,  readily  sol.  in  aq.  and  in 
alcohol,  less  sol.  in  ether.  Acids  precipitate  it  from  aqueous  solutions. 

DRY  TESTS. — On  heating,  tannin  melts,  blackens  and  yields  H2O,  CCV, 
and  pyrogallol,  the  last  condenses  in  yellowish  drops  and  crystallizes  on 
cooling. 

H2S04  '  red  colour. 

WET  TESTS. — Diss.  '02  gm.  in  10  c.c.  of  aq. 

NaOH  in  excess  :  a  brown  colour  changing  to  red  and  then  to  yellow. 

FeCls  with  neutral  sols.  :  a  blue-black  ppt.  (ink). 

Gelatin  sol.  :  stringy  ppt.  (leather) ;  gallic  acid  and  pyrogallol  do  not 
coagulate  gelatine. 

KCy,  shake  :  brown-red  colour. 

K3FeCyr,  and  NH4OH  :  deep  red  colouration. 

Pb2NOs  :  white  ppt.  of  Pb  tannate.  (Distinction  from  gallic  acid  and 
pyrogallol.) 

Fehling-'s   solution  :  reduced  on  boiling. 


Pyrogallol,  Pyrogallic  Acid.    Cr,H.s(OH)3. 

Acicular  colourless  crystals;  poisonous.  Melts  131°,  boils  210°;  very 
sol.  in  water,  alcohol,  and  ether,  less  sol.  in  chloroform  and  benzene. 

DRY  TESTS. — Heated  in  tube  :  black  mass  sol.  in  alkalis. 

H2S04  (cone.)  :  colourless  sol.,  darkens  on  heating. 

NaOH  or  KOH  :  solution,  which  rapidly  darkens  from  absorption  of 
oxygen. 

WET  TESTS. — Diss.   *02  gm.  pyrogallol  in  8  c.c.  aq. 

Tartarie  acid,  and  i  c.c.  cone.  H2S04,  warm  :  violet  colour. 


MKCONIC     ACID     AND     URIC     ACID  53 

FeCla  :  green  colour* 
FeS04  '•  bright  blue  colour. 
Ca02H2  '  purple  colour,  changing  to  brown. 
Fehling's   solution  :  red  ppt.  of  Cu2O. 
Ag-NOs  :  ppt.  of  metallic  silver. 

Formaldehyde,  2  drops,  and  2  drops  (cone.)  H2S04  :  white  ppt.,  changing 
to.  red  and  purple. 


Meconic  Acid. 

Occurs  in  opium,* as  morphine  meconate.  Colourless  rhombic  prisms  or 
in  plates  ;  readily  sol.  in  alcohol  and  in  hot  water,  sparingly  sol.  in  cold  aq. 

DRY  TESTS. — Heated  in  1  tube  at  100°  C.  :  water;  at  120°  :  CO2  and 
comenic  acid  (CGH4O5)  and  at  higher  temps.  :  chars  and  emits  odour  of 
caramel. 

WET  TESTS. — Diss.  'ooi  gm.  in  C2H5OH  and  dilute  to  6  c.c. 

H2S04  (cone.)  :  no  change. 

AgNOs  :  pale  yellow  flocculent  ppt.  of  Ag  meconate,  sol  in  NH4OH. 

FeCl3  :  dusky  purple  colour ;  boil  :  a  ppt.  of  basic  ferric  meconate. 

CaCl2,  stir  with  glass  rod  :  white  silky  ppt.   of  Ca   meconate. 

Pb2C2H302  :  pale  }rellow  ppt.,  insol.  in  acetic  acid  but  sol  in  dil.  HNO3. 

CuS04  and  one  drop  of  NH4OH  :  green  ppt. 


Uric  Acid.    C5ILN403  or  (NH)4C2(CO)3. 

Colourless  crystals  only  slightly  sol.  in  aq. ,  insol.  in  alcohol  and  ether. 
Dissolves  in  KOH  and  NaOH,  and  in  sols,  of  salts  possessing  an  alkaline 
reaction. 

DRY  TESTS. — Heated  in  tube  :  does  not  melt,  gives  orFNH3,  cyanic  acid 
and  HCy  ;  cyanuric  acid  (HCyO)2  is  left.  Heated  with  NaOH  :  NH3  and 
NaCy  ;  the  residue  gives  Prussian  blue  with  FeSO4. 

HN03  dissolves  uric  acid  with  effervescence,  the  sol.  slowly  evaporated  to 
dryness  on  a  W.B.  and  moistened  with  NH4OH  yields  a  crimson  colour 
(murexide)  ;  NaOH  changes  this  to  purple. 

H2S04  :  sol.,  does  not  char  when  heated ;  CO,  CO2  and  SO2  evolved. 

WET  TESTS. — Diss.  -oi  gm.  of  Na  urate  in  i  c.c.  NaOH. 

HC1  :  white  ppt.  of  uric  acid. 

Diss.  *oi  gm.  uric  acid  in  i  c.c.  of  Na2CO3  and  place  a  drop  on  filter 
paper  moistened  with  AgNO3  :  black  stain  of  reduced  Ag. 
Fehling's  solution  is  reduced  on  warming. 


54  HIPPURIC    ACID 

Hippuric  Acid.    C9IL08. 

Colourless  prisms,  bitter  taste,  acid  reaction,  slightly  sol.  in  aq. 

DRY  TEST. — Heated  with  soda  lime  :  NH3  and  benzene  (C6H(i)  are 
evolved. 

WET  TESTS. — Diss.  'I  gm.  of  hippuric  acid  in  dil.  NH4OH  and  boil  off 
any  excess  of  NH4OH. 

HC1  :  white  ppt.  of  hippuric  acid. 

FeCls  •  flesh-coloured  ppt. 

Ag-NOs  :  white  ppt. 


MKTHYL     ALCOHOL     AND     ETHYL     ALCOHOL  55 


AL,COHOL,S    AND   THEIR   DERIVATIVES. 


Methyl  Alcohol  (Wood  Spirit).     CILOH. 

Colourless  volatile  liquid  with  a  ' '  spirituous  ' '  odour.  Neutral,  boils  60°, 
burns  with  non-luminous  flame.  Sp.  gr.  "7972.  When  mixed  with  aq., 
heat  is  evolved  and  the  volume  contracts. 

Use  '5  c.c.  for  each  test. 

H2S04  (cone.),  warm  :  dimethyl  ether,  recognised  by  its  odour. 

H2S04  and  Na  formate  :  characteristic  odour  of  methyl  formate. 

H..S04  and  '01  gm.  salicylic  acid,  warm  :  odour  of  oil  of  winter  green 
(methyl  salicylate). 

H.,S04  (i  to  i  aq.)  5  c.c.  and  i  gm.  of  K2Cr207  and  5  c.c.  methyl  alcohol, 
distil  from  a  test  tube  and  test  the  distillate  for  formic  acid. 


Ethyl  Alcohol  (Spirit  of  Wine).    C2H5.0H. 

Colourless  volatile  liquid  with  characteristic  odour  and  burning  taste. 
Sp.  gr.  '7938  at  15*5  ;  boils  78*4°  C.,  and  burns  with  a  non-luminous  flame. 
When  mixed  with  aq.,  heat  is  evolved  and  the  vol.  contracts  ;  mixes  with 
ether  and  carbon  bisulphide  in  all  proportions.  Dissolves  many  salts,  oils, 
resins,  etc. 

Use  '5  c.c.  for  each  test. 

H2S04  (cone.),  warm  :  ether  and  ethene  (C2H4)  which  burn  with  a  luminous 
flame. 

Aldehyde  test.  Add  K2Cr207  and  H2S04,  warm  :  odour  of  aldehyde 
(CH3.CHO)  and  the  solution  becomes  green.  Distil  and  test  distillate  for 
aldehyde  by  the  rosaniline  test. 

H2S04  (cone.),  warm  with  strong  alcohol  and  i  gm.  solid  Na  formate  or 
Na  acetate,  or  Na  benzoate,  etc.,  :  the  well-marked  odour  of  formic, 
acetic,  benzoic  or  other  ether. 

lodoform  test.  Add  '5  c.c.  Na2C03  and  sol.  of  iodine  in  KI,  drop  by 
drop,  until  the  sol.  retains  a  brown  colour,  warm  to  60°  C.  ;  on  cooling, 
iodoform  (CHI8)  separates  in  yellow  six-rayed  crystals ;  the  ppt.  and  sol. 
have  a  peculiar  saffron-like  odour.  Aldehyde,  acetone,  acetic  ether,  etc. , 
also  yield  iodoform. 


56  AMYL    ALCOHOL     AND    ETHER 

KOH  and  CS2  :  yellow  ppt.  of  pot.  xanthate  KC2H5COS2,  to  this  add 
CuSO*  and  HC1  :  a  brown  ppt.  of  copper  xanthate,  this  becomes  bright  yellow 
and  emits  an  offensive  odour. 

Hg2N03>  boil  :  white  ppt.  of  HgNO3,  on  adding  NH4OH  it  becomes  grey 
or  black.  (Distinction  from  methyl  alcohol.) 

To  detect  methyl  alcohol  in  ethyl  alcohol. 

Add  K2Cr207  and  H2S04  to  oxidize  them  into  formic  and  acetic  acids  ; 
allow  to  stand  for  some  time ;  distil,  add  a  slight  excess  of  Na2C03  to  the  dis- 
tillate and  concentrate  ;  acidulate  with  acetic  acid  ;  add  AgNO3  and  warm,  if 
much  metallic  Ag  is  reduced  (due  to  formic  acid)  then  methyl  alcohol  is 
present. 


Amyl  Alcohol. 

Colourless,  oily  liquid,  strong  odour,  causes  coughing ;  only  slightly 
sol.  in  aq.  ;  boils  132°  C. 

Use  '5  c.c.  for  each  test. 

H2S04  (cone.),  warm  :  reddish  brown  colour,  next  add  '5  c.c.  glacial 
acetic  acid  and  i  c.c.  FeCl3  and  warm  again  :  a  purple  colour. 

Na  acetate,  about  'i  gm.  and  5  c.c.  H2SO4,  warm  :  odour  of  pears,  due 
to  the  amyl  acetate,  intensified  by  pouring  the  mixture  into  water  ;  this 
applies  to  the  following  test  also. 

K2Cr207  about  'i  gm.  and  5  drops  H2S04,  warm  :  odour  of  amyl  valerate 


Ether  (Ethyl  Oxide).    (C2IQ.O. 

Mobile,  colourless  liquid,  with  a  characteristic  pleasant  ethereal  odour 
and  sweet  taste;  very  -inflammable,  burns  with  a  luminous  flame. 
(Alcohol  burns  with  a  non-luminous  flame.)  Mixtures  of  ether  vapour 
and  air  explode  violently  on  ignition.  Sp.  gr.  736  at  o°  C.,  boils  34*6°  C. 
Very  volatile,  when  placed  on  the  skin  it  produces  a  feeling  of  great  coldness. 

Magenta  (rosaniline  acetate)  is  insol.  in  ether,  if  dry  and  free  from 
alcohol. 

Mixes  with  absolute  alcohol  and  CS2,  but  i  part  of  ether  requires  9 
parts  of  aq.  for  its  solution. 

Dissolves  fats,  oils,  resins,  india  rubber,  phosphorus,  iodine,  sulphur, 
etc.,  readily. 

'Cl  and  Br  act  upon  it  readily. 

Na  and  K  do  not  act  upon  it. 


FORMALDEHYDE,    ACETAI<DEHYDE    AND    CHLORAI,    HYDRATE         57 

Formaldehyde.    H.CHO. 

A  gas  with  peculiar  pungent  odour.  "  Formalin  "  is  a  40  per  cent.  sol. 
in  aq.  On  evaporation  over  a  W.  B.  :  solid  paraformaldehyde. 

Use  '5  c.c.  for  each  test. 

AgN03  and  NH4OH,  place  the  test  tube  in  hot  water  :  a  silver  mirror. 

Fehling's  solution,  warm  :  ppt.  of  CuoO. 

Magenta  (or  fuchsine)  reduced  by  S02,  has  its  colour  restored  by  formal- 
dehyde. 

Pyrogallol  (freshly-prepared  solution)  and  excess  of  strong  HC1,  on  stand- 
ing :  a  white  ppt.  which  gradually  becomes  magenta  coloured. 

Phenyl  hydrazine  hydroehloride,  3  drops  of  Na  nitroprusside,  (5  per  cent, 
sol.),  10  drops  NaOH  (10  per  cent,  sol.)  :  blue  colour. 

K3FeCyG  •  scarlet  colour. 

Acetaldehyde.    CIL.CHO. 

Colourless  mobile  liquid,  very  volatile  and  inflammable;  boils  at  21°; 
choking  odour  ;  mixes  with  aq. ,  alcohol  and  ether. 

Use  '5  c.c.  for  each  test. 

AgN03  and  NH4OH.  warm  :  a  mirror  of  reduced  silver. 

Magenta,  reduced  by  S02,  has  its  colour  restored  by  aldehyde. 

KOH  (cone.)  warm,  on  standing  :  a  yellow  ppt.  of  aldehyde  resin. 

Fehling's  solution  :  red  ppt.  of  Cu2O. 

NaHS03  :  crystals  of  CH3.CHO.NaHSO3. 

Pyrogallol  and  strong  HC1,  let  stand  :  white  ppt.,  which  gradually  be- 
comes yellow.  (See  formaldehyde.) 


Chloral  Hydrate.     CC13.CHO.H20. 

Crystallized,  greasy  feel,  disagreeable  odour,  bitter  taste,  melts  readily, 
boils  and  condenses  in  drops  which  crystallize. 

Dissolves  readily  in  aq.,  alcohol  and  ether;  rotates  on  the  surface  of 
water  like  camphor. 

WET  TESTS. — Diss.   T  gm.  in  5  c.c.  of  aq. 

KOH  :  turbid,  from  separation  of  chloroform,  which  re-dissolves,  but  can 
be  recognised  by  its  odour. 

AgN03  and  NH4OH  (dil.)  :  odour  of  chloroform,  and  ppt.  of  metallic  Ag. 

Aniline  and  KOH  in  alcohol,  warm  :  the  offensive  odour  of  phenyl  isocy- 
anide.  (See  chloroform.) 

Fehling's  solution,  warm  :  ppt.  of  Cu.2O. 


5&  ACETONK    AND    CHLOROFORM 

Acetone  (Di-methyl  Ketone).     CH3.CO.CH3. 

Colourless  mobile  inflammable  liquid,  with  ethereal  odour,  mixes  with 
aq.,  alcohol  and  ether;  boils  56-5°. 

Use  '5  c.c.  for  each  test. 

Iodine  or  Iodine  in  KI,  then  Na2C03  until  the  brown  colour  disappears, 
warm  :  iodoform  (CHI3)  which  crystallizes  out  on  cooling. 

HgCl2,  and  NaOH  drop  by  drop  to  excess,  shake,  and  if  necessary  filter,  the 
sol.  contains  HgO  ;  acidify  with  HC1  and  add  SnCl2  :  ppt.  of  HgCl  or  Hg. 

NH4OH,  and  Iodine  in  KI  drop  by  drop  until  a  trace  of  black  iodide  of 
nitrogen  forms,  then  warm  carefully  ;  on  cooling  CHI3  crystallizes  out.  (Dis- 
tinction from  ethyl  alcohol.) 

NaHSOa  :  crystals  of  C3HGO,NaHSO3.  Advantage  is  taken  of  this  re- 
action commercially  to  purify  acetone. 

Na  nitroprusside  (fresh  dil.  sol.)  and  strong  KOH  :  a  red  colour  fading  to 
yellow  (NH4OH  :  purple) ;  on  acidifying  with  acetic  acid  the  solution 
becomes  purple. 


Chloroform.     CHCL 

Colourless  liquid  with  a  characteristic  pleasant  odour  and  burning  taste, 
very  volatile,  boils  6i'2°  C.,  but  not  readily  combustible  ;  readily  sol.  in 
alcohol,  ether,  and  carbon  bisulphide  ;  only  slightly  sol.  in  water.  Dissolves 
fats,  oils  and  resins. 

Use  *5  c.c.  for  each  test. 

KOH  (strong)  and  ten  times  its  vol.  of  alcohol,  warm  :  KCI  and  K 
formate  ;  to  confirm,  add  dil.  H2SO4  and  distil  ;  test  the  distillate  for  formic 
acid. 

KOH  (in  alcohol)  and  two  drops  of  aniline,  warm  :  the  nauseous  odour  of 
phenyl  isocyanide  (carbylamine  C6H5NC). 

Fehling's  solution,  warm  :  ppt.  of  Cu2O. 

Phenol  and  KOH  (in  alcohol),  evaporate  to  dryness  on  W.B.  and  moisten 
with  CHC13  :  a  purple  colour.  (Distinction  from  chloral.) 

TKSTS   FOR   IMPURITIES. 

Pure  chloroform  leaves  no  residue  on  evaporation  in  a    watch   glass. 

Gives  no  ppt.  when  shaken  with  AgNO3. 

Does  not  act  on  litmus  paper. 

Does  not  turn  K2Cr2C>7  and  H2SO4  green  in  the  cold. 

Does  not  oxidize  bright  sodium. 

Does  not  turn  brown  with  either  strong  KOH  or  strong  H2SO4. 


GLYCEROI,,    HYDROXYI,    AND    CARBON    BISULPHIDE  59 

Glycerol  or  Glycerin.     C3H5(OH)3. 

A  colourless,  odourless,  oil-like  liquid,  neutral,  with  sweet  taste ;  boils 
290°,  and  yields  acrolein  (C2H3.CHO)  recognised  by  its  disagreeable  odour. 
Very  hygroscopic,  mixes  with  aq.  and  alcohol  in  all  proportions  ;  almost 
insol.  in  chloroform  and  in  ether. 

Marks  paper  like  oil,  but  the  stain  is  removed  on  soaking  in  aq. 

Use  '5  c.c.  for  each  test. 

Heated  alone,  or  with  HJSCh,  KHS04,  or  P205  :  the  disagreeable  odour  of 
acrolein  is  evolved. 

NaOH,  heat  :  no  change. 

Borax  bead  moistened  with  glycerol  and  heated  in  the  outer  edge  of  the 
bunsen  flame  gives  a  momentary  green  colouration. 

Sulphur,  boil  :  unpleasant  odour  of  allyl  mercaptan,  etc. 

Phenol,  H2S04  and  glyeerol,  each  two  drops,  mix,  heat  to  about  120° ;  add 
water  and  excess  of  NH4OH  :  crimson  colour. 


UNCLASSIFIED. 


Hydroxyl.     ILCk 

Colourless  liquid  without  odour;   generally  used  as  a   10  vol.   sol.  in 
water.   Decomposed  on  warming  (oxygen  evolved)  and  by  organic  substances. 
TESTS. — Use  i  c.c.  for  each  test. 
Litmus  sol.  :  Bleached. 
KMn04  sol.  :  Bleached. 
PbS  :  Converted  into  white  PbSO4. 

KI  and  starch  paste  :  blue  colour  from  the  liberation  of  iodine. 
Ether  and  KaCraO?  sol.,  shake  :  evanescent  blue  colour. 


Carbon  Bisulphide.     CS2. 

Colourless,  mobile,  highly  refractive  liquid,  odour  usually  offensive,  but 
ethereal  when  pure.  Sp.  gr.  1-292.  Very  volatile,  boils  46-6°  C.,  its  vapour 
is  extremely  inflammable  (can  be  ignited  by  a  test  tube  containing  hot  oil) ; 
yields  SO2  when  burnt ;  if  with  insufficient  air,  in  a  beaker  6*r  tube,  S  is 
deposited. 

Almost  insol.  in  aq.,  but  readily  sol.  in  alcohol  and  ether.  It  readily 
dissolves  S,  P,  I,  caoutchouc,  oils  and  fats. 

Use  '5  c.c.  for  each  test. 


60  UREA 

KOH,  boil  :  brown  sol.  of  K2CO3  and  K2CS3  ;  add  one  drop  of  Pb  acetate  : 
black  PbS. 

H2S04  (cone.)  on  shaking  :  ppt.  of  S. 

KOH  (in  alcohol)  shake  :  crystals  of  pot.  xanthate. 


Urea  (Carbamide)      CO(NH2)2. 

Crystallizes  in  four-sided  prisms,  deliquescent,  very  sol.  in  aq.  and  in 
alcohol,  very  slightly  in  ether.  Melts  132°  ;  taste  resembles  saltpetre. 

DRY  TKST. — Heat  '01  gm.  in  a  dry  tube  :  evolves  NH3,  etc.,  the  residue 
contains  cyanuric  acid  and  biuret,  a  sublimate  of  biuret  is  also  formed ;  ex- 
tract the  biuret  with  warm  water,  filter,  add  to  filtrate  a  drop  of  dil.  CuSO4 
and  excess  of  NaOH  :  purple  colour. 

Heated  with  NaOH  or  Na2C03  :  NH3. 

WET  TESTS. — Diss  *i  gm.  of  urea  in  7  c.c.   aq. 

HN03  (free  from  HNO2)  :  crystals  of  urea  nitrate  (only  from  strong  sols.). 

H2C204  (oxalic  acid)  :  tabular  prisms  of  the  oxalate  (only  from  strong  sols.). 

Hg2N03  :  a  flocculent  ppt.  of  CO(NH2).2.2HgO,  even  in  very  dil.  sols.,  sol. 
in  NaCl,  reprecipitated  by  further  addition  of  Hg2NO3. 

KBrO  (or  KC10)  :  decomposes  urea  with  effervescence  into  CO2,  H2O  and  N. 
(KBrO  can  be  made  by  adding  cold  KOH  to  Br  aq.  until  decolourized.) 

HN02  (nitrous  acid)  or  a  sol.  of  KN02  and  dil.  HgSO*  (or  HC2H3O2)  decom- 
poses urea  into  N  and  COa. 


CARBOHYDRATES. 


SUGARS,  AMYLOIDS  AND  CEU^ULOSE. 


Glucoses. 

DKXTROSK  (Grape  Sugar),  C6Hi2O6,H2O.  Crystallized,  colourless,  and 
without  odour  ;  less  sweet  than  cane  sugar. 

The  crystallized  sugar  melts  at  80°  to  86°  ;  the  anhydrous  at  146°.  Sol. 
in  aq.  and  in  dil.  alcohol,  insol.  in  ether. 

Dextrorotatory,  [#]D  =  +  52*5°;  readily  ferments  with  yeast.  Its 
osazone  melts  at  206°. 

DRY  TESTS.  —  Heated  :  turns  brown  and  evolves  odour  of  caramel. 

EUSO^  (cone.)  :  no  change  ;  warm  :  dark  brown  colour.     (See  sucrose.) 

WET  TESTS.  —  Diss.  o'i  gm.  in  6  c.c.  aq. 

KOH  (strong),  warm  :  brown  solution  ;  on  adding  HNO3  changes  to 
yellow  and  the  odour  of  caramel  is  evolved.  (Compare  with  cane  sugar.) 

Pb  acetate,  boil,  add  NH4OH  until  a  white  ppt.  just  forms,  boil  :  the  ppt. 
becomes  pink  colour.  (Cane  and  milk  sugars  do  not  give  this  reaction.) 

Cu  acetate  and  two  drops  of  acetic  acid,  warm  :  ppt.  of  red  Cu2O.  (See 
milk  sugar.) 

AgNOs  and  NH4OH,  place  the  test  tube  in  a  beaker  of  boiling  water  :  a 
silver  mirror  forms  on  the  test  tube. 

Fehling's   solution  :  reduced  immediately  on  warming. 

KOH  and  3  drops  of  picric  acid  sol.,  boil  :  the  yellow  colour  changes 
slowly  to  red  (picramic  acid),  C«H2.OH.NH2.(NO2),. 


(Fruit  Sugar),   CcH^O,,. 
Is  distinguished  from  dextrose  by  its  rotating  the  polarised  ray  to  .the 
left,  [rt]D=  -  1  13*9°  ;  by  being  more  sol.  in  aq.  and  in  alcohol,  and  by  yielding 
a  ppt.  with  Ca(OH)2. 


Saccharoses. 

SUCROSE  (Cane  Sugar).  Crystallized  in  colourless  oblique  prisms  ; 
readily  sol.  in  aq.,  but  sparingly  sol.  in  alcohol.  Melts  at  160°,  when  cold 
is  vitreous,  i.e.,  non-crystallized  (barley  sugar).  Dextrorotatory,  [tf]D=  + 
66  '5°.  Cane  sugar  does  not  form  an  osazone. 

DRY  TEST.  —  Heated  to  about  200°  it  changes  to  caramel  (brown),  then 
chars,  evolves  gases  and  a  characteristic  odour. 

61 


62  SACCHAROSES 

H2S04  (cone.),  chars  sugar  and  syrup. 

WET   TESTS. — Diss.  o'i  gm.  in  5  c.c.  aq. 

KOH  (strong),  heat,  does  not  become  brown,  nor  is  the  odour  of  caramel 
emitted  on  acidifying  with  HNO3.  (See  glucose.) 

Cu  acetate  alone,  or  when  warmed  with  acetic  acid,  is  not  reduced. 
(See  glucoses.) 

AgN03  and  NH4OH,  warm  :  no  silver  mirror. 

Pb  acetate  and  NH4OH,  boil,  the  white  ppt.  does  not  become  yellow. 

Fehling's  solution  is  not  reduced  (by  a  fresh  sol.  of  sugar) ;  if,  however, 
the  sugar  be  previously  "inverted"  by  warming  with  2  drops  of  HC1  or 
H.2SO4,  Fehling's  solution  is  quickly  reduced  on  warming. 

lyACTQSE  (Milk  Sugar).     C,2H22On,H2O. 

Crystallizes  in  prisms,  gritty  and  not  so  sweet  as  cane  sugar;  sol.  in  aq., 
insol.  in  ether  and  absolute  alcohol.  Dextrorotatory,  [tf]D  =  +  52*53°.  Its 
osazone  melts  at  200°  ;  does  not  ferment  with  yeast. 

DRY  TESTS. — Heated,  becomes  brown. 

H2S04  (cone.),  warm  :  blackens  or  chars,  but  less  readily  than  cane  sugar. 

WET  TESTS. — Diss.   -i  gm.  in  6  c.c.   aq. 

KOH,  boil  :  brown  colour,  discharged  on  adding  dil.  HNO3,  and  odour  of 
caramel  evolved. 

Cu  acetate  (and  2  drops  of  acetic  acid)  on  boiling  and  standing  is  not 
reduced  unless  the  solution  be  concentrated. 

AgNOa  and  NH4OH  :  Ag  mirror  when  warmed. 

Pb  acetate,  boil  and  add  just  sufficient  NH4OH  to  produce  a  ppt.,  again 
boil,  the  white  ppt.  becomes  pale  yellow ;  the  ppt.  from  cane  sugar  remains 
white  and  that  from  glucose  becomes  pink. 

KOH  and  picric  acid,  boil  :  red  (picramic  acid). 

Fehling's  solution,  warm  :  red  ppt.  of  Cu2O. 

MAI/TOSE. — Ci2H22On,H2O.  Crystallized,  very  sol.  in  aq.,  almost  insol. 
in  absolute  alcohol;  readily  fermented.  Dextrorotatory,  [«]D=  +  140*6°. 
Its  osazone  melts  206°. 

DRY  TEST. — Moisten  the  powder,  add  cone.  H2SO4  :  clear  sol.,  chars  on 
warming. 

WET  TESTS. — Diss.    *i  gm.  in  5  c.c.   aq. 

NaOH,  boil  :  yellow,  then  brown  colour,  dil.  HNO3  discharges  the  colour 
and  the  odour  of  caramel  is  evolved. 

Fehling's  solution,  boil  :  red  ppt.  of  Cu2O. 

Cu  acetate,  and  2  drops  of  acetic  acid,  is  not  reduced  on  boiling. 

Pb2C2H302  and  NH4OH  :  white  ppt.,  which  becomes  pink  on  boiling. 
(See  glucose.) 


SACCHAROSES. 


Picric  acid  and  NaOH  :  red  picramic  acid    (C6H2,NH2(NO2)2OH). 
cose  and  lactose  also  give  this  reaction. 


63 
Glu- 


GENERAI,   REACTION. 

(a)  When  a  molecule  of  a  sugar  containing  an  aldehyde  (CHO)  or  a 
ketone  group  (CO)  is  acted  upon  by  phenyl  hydrazine  it  yields  a  hydrazone. 

j  CH2(OH)(CH.OH)4CHO  +  (  C6H6NH.NH8  = 
I  Glucose  (  Phenyl  hydrazine 

H20  +    (  C6H5NH.N:HC(CH.OH)4(OH)CH2 
I  Glucose  phenylhydrazone 

(b)  When  an   "excess"    of    phenylhydrazine  is    added  the  CH(OH) 
group  next  the  end  is  oxidized  to  CO,  and  part  of  the  phenyl  hydrazine  is 
reduced  to  aniline  and  NH3,  and  the  oxidation  product  of  the  phenyl  hydra- 
zone  combines  with  a  second  molecule  of  phenyl  hydrazine  and  yields  an 

osazone. 

CH,.(OH)(CH.OH)3CO.CH:N.NH.C6H5  +  (  C6H5NH.NH2  = 

(  Phenyl  hydrazine 

CH2(OH)(CH.OH)3C(N.NHCGH5)CH:N.NH.C6H5  +  H2O 
Osazone 

KXPT. — Diss.  '5  gm.  of  a  sugar  in  5  c.c.  aq.,  add  3  c.c.  phenyl  hydra- 
zine and  3  c.c.  acetic  acid,  place  the  test  tube  in  boiling  water  for  about  ten 
minutes,  when  the  osazone  comes  down  as  yellow  crystals. 

To  identify  the  sugar,  filter  off  the  osazone,  wash,  dry  and  determine  its 
melting  point  or  examine  its  decomposition  products. 

SUMMARY   OF  SUGAR   REACTIONS. 


TEST. 

GLUCOSE. 

SUCROSE. 

ivACTOSE. 

MAI/TOSE. 

Rotation 

[«]D=  +  52-5°. 

[«]„=+  66'5°. 

[«]D=  +  52-530. 

[«]D  -  +  I40'6°. 

Heated  alone 

Browns  and  yields 

Yields  barley  su- 

Browns. 

caramel. 

gar  and  caramel. 

H2SO4  (cone.) 

No  change,  chars 

Chars  in  the  cold. 

Chars  on  heating. 

Chars  on  heating. 

on  warming. 

NaOH  sol.,  heated 

Becomes    brown  ; 

No  change. 

Becomes    brown  ; 

Becomes    brown  ; 

add  HNO;}  =  car- 

add HNO«  =  car- 

add  HNO3  =  car- 

amel odour. 

mel  odour. 

amel  odour. 

Pb.    acetate    and 

Pink  ppt. 

White  ppt. 

Yellow  ppt. 

Pink  coloured  ppt. 

NH4OH 

• 

Cu     acetate     and 

Cu2O  on  boiling. 

No  change. 

No  change. 

No  change. 

acetic  acid 

Fehling's  sol. 

Cu2O  on  boiling. 

No  change. 

Cu2O  on  boiling. 

Cu2O  on  boiling 

Pheuyl  hydrazine 

Yellow  crystals  of 

No  osazone. 

Yellow     crystals, 

Yellow  crystals  of 

glucosazone,  m.p. 

Ivactosazone. 

Maltosazone 

206°. 

m.p.  200°. 

m.p.  206°. 

64  AMYLOIDS 

Amyloids.    (CoHio05)n 

STARCH. — White  powder,  with  peculiar  harsh  feel  when  rubbed  between 
the  ringers.  Under  the  microscope  the  grains  of  many  varieties  of  starch  are 
seen  to  be  made  up  of  concentric  layers,  and  to  show  a  well-marked  cross 
with  Nicol's  prisms.  Insol.in  cold  aq.  ;  in  hot  aq.  the  granules  burst  and 
yield  a  translucent  fluid,  strong  sols,  set  to  a  jelly  :  "starch  paste  " 

DRY  TESTS. — When  heated  (to  150°  C.)  it  is  changed  into  dextrin  (or 
British  gum)  which  is  sol.  in  aq. ,  and  gives  a  reddish  colour  with  tincture  of 
iodine,  instead  of  blue.  At  higher  temps,  it  chars  and  emits  an  unpleasant 
odour. 

WET  TKSTS. — Grind  *oi  gm.  starch  with  i  c.c.  of  cold  aq.,  make  up  to 
5  c.c.  with  aq.  and  boil. 

Iodine  (tincture)  :  a  blue  colour,  which  disappears  on  boiling,  but  returns 
when  cold,  if  not  boiled  too  long. 

Reducing  substances,  e.g.,  Na2SO3,  Na,S2O3,  and  SH2  prevent  the 
formation  of  the  blue  colour ;  if  such  are  present,  add  3  drops  of  K<jCraO7 
and  5  of  HC1. 

H2S04  (cone.),  warm  :  blackens,  CO2  and  SO2  evolved. 

H2S04  (dil.),  warm  .for  some  time  :  a  mixture  of  dextrose  and  dextrin, 
add  iodine  :  red  colour. 

Alcohol  (excess)  :  white  ppt. 

Basic  Pb  acetate,  Ba(OH)2,  Ca(OH)2,  tannin,  etc.,  also  ppt.  starch. 

Br  aq.  to  a  sol.  of  starch  in  HC1  :  yellow  colour. 

Fehling's  solution  :  ppt.  of  Cu2O.  (Test  for  dextrose  by  boiling  with  Cu 
acetate  and  acetic  acid  :  Cu2O  ppt.) 

Diastase  and  certain  other  enzymes  convert  it  into  a  mixture  of  dextrin 
and  maltose. 

INUUN,  a  variety  of  starch  from  chicory,  artichokes,  dahlia  tubers,  etc., 
is  coloured  yellow  by  iodine. 

.  DEXTRIN  (British  Gum).     (C6H10O5)n. 

Amorphous  powder,  readily  softens  and  is  sol.  in  cold  aq. ;  gum-like 
taste  ;  insol.  in  strong  alcohol. 

WET  TESTS. — Boil  'i  gm.  in  5  c.c.  aq. 

Iodine  (tincture)  :  reddish  colour  ;  the  commercial  article  gives  a  blue 
colour  with  I. 

HC1,  H2S04,  and  HN03  (dil.)  on  boiling  convert  it  into  dextrose. 

Cu  acetate  :  slowly  reduced  on  warming. 

Fehling's  solution  slowly  reduced  on  boiling. 

Tribasie  lead  acetate,  no  ppt.,  add  NH4OH  :  ppt. 


GUM     ARABIC  65 

GUM  ARABIC.  The  chief  constituent  is  the  Ca  salt  of  arabic  acid, 
(C6H1005). 

Occurs  in  yellow  or  colourless  translucent  drop  or  tears,  softens  in  cold 
water ;  composed  of  arabic  acid  and  mineral  matter. 

Heated  :  fuses,  gives  off  odour  of  caramel,  and  leaves  a  white  ash. 

WET  TESTS. — Diss.    'i  gm.  in  5  c.c.  aq. 

Iodine  (tincture)  :  no  colour,  hence  distinguished  from  starch,  dextrin,  etc. 

Ca(OH)2,  KOH  and  NaOH  each  give  white  ppts.  of  gum  arabic,  but  if 
mineral  acids  (e.g.,  HC1)  be  present,  arable  acid  is  pptd. 

Alcohol  :  white  ppt. 

CuS04  sol.  and  excess  of  NaOH  :  a  bluish  ppt.,  not  reduced  or  blackened 
on  boiling,  as  is  the  case  with  dextrin  and  the  sugars. 

Basic  Pb  acetate  :  a  white  gelatinous  ppt.  This  also  distinguishes  it 
from  dextrin  and  sugar. 

CEIXULOSE.     (C6H10O5)n. 

Use  '01  gm.  of  cotton  wool  for  each  test. 

H2S04  (cone.)  :  solution,  reprecipitated  on  dilution. 

Cu(OH)2  in  strong1  NH8  :  solution  ;  reprecipitated  on  dilution  and  by  acids. 

ZnCla  :  solution,  which  does  not  become  blue  with  iodine. 

H.2S04  (dil.),  boil  :  converted  into  dextrose  and  dextrin. 

KOH,  Ba(OH)2,  etc.  :  form  salts. 

HN03  (cone.)  converts  it  into  guncotton. 


GIvlJCOSIDES. 


Glucosides  are  vegetable  compounds,  which  when  acted  upon  by  acids 
or  alkalis  generally  yield  glucose  and  one  or  more  other  substances. 

SALICIN.  (Ci3Hi8O7).  Crystallizes  in  silky  needles  ;  bitter  taste  ;  melts 
196°.  Sol.  in  alcohol,  KOH,  NaOH,  glacial  acetic  acid,  in  30  parts  of  cold 
and  in  i  of  hot  water,  but  insol.  in  ether. 

DRY  TEST. — Heated  in  a  dry  tube  it  melts,  chars  and  emits  the  odour 
of  caramel. 

COLOUR  TESTS. — Use  'ooi  gm.  for  each  test. 

H2S04  (cone).,  on  watch-glass  or  porcelain  :  red  colour. 

Mandelin's  reagent  (see  index)  :  purple  colour. 

Froehde's  reagent  (see  index)  :  violet  colour. 

Erdmann's  reagent  (see  index)  :  red,  with  purple  edges. 

WET  TESTS. — 

H2S04  (dil.),  warm  :  glucose,  C(!H12O6,  and  saligenin  C6H4CH2(OH)2, 
now  warm  with  2  c.c.  Fehling's  sol.  :  ppt.  of  Cu2O. 

K2Cr207  (powder)  and  (cone.)  H2S04  added  to  the  above  hydrolysed  solution 
on  warming  :  salicylal,  recognised  by  its  odour  of  oil  of  meadow  sweet. 

AgN03,  NH4OH,  and  2  drops  of  KOH,  warm  :  mirror  of  reduced  silver. 

DIGITALIN.  (C29H46Oi2).  White  powder  ;  melts  217°.  Readily  sol.  in 
aq.  and  hot  absolute  alcohol,  sparingly  sol.  in  cold  alcohol,  ether  and 
chloroform.  Does  not  evolve  nitrogenous  odour  when  heated. 

COLOUR  TESTS. — Use  'ooi  gm.  for  each  test. 

H2S04  (cone.)  :  yellow,  brown,  and  finally  red. 

H2S04  (cone.)  and  K2Cr207  (powdered)  :  brown,  changing  to  green. 

H2S04  (cone.),  stir  with  rod  dipped  in  Br  aq.  :  red-brown  colour. 

Erdmann's  and  Froehde's  reagents  :  brown  colour. 

Mandelin's  reagent  :  red-brown,  changing  to  cherry-red. 

WET  TESTS. — 

AgN03,  NH4OH,  and  a  drop  of  KOH,  warm  :  silver  mirror. 


66 


AROMATIC    COMPOUNDS. 


Benzene.    C6H6. 

Mobile  colourless  liquid,  with  characteristic  (coal  gas-like)  odour.  Boils 
80°  C.  ;  sp.  gr.,  '88;  very  volatile;  burns  readily  with  a  luminous  smoky 
flame  ;  almost  insol.  in  H2O,  readily  sol.  in  alcohol  and  ether. 

WET  TESTS. — Use  5  drops  for  each  test. 

H2S04  (cone.)  :  no  change. 

HN03  (cone.),  mixed  with  cone.  H2S04  ;  when  the  action  ceases  pour  into 
a  beaker  of  aq.  :  nitro-benzene  (C6H5.NO2)  separates  out  as  yellow  oily  drops. 
Note  the  odour  of  bitter  almonds. 

NOTE. — Benzine  or  benzoline  is  a  mixture  of  the  light  paraffin  oils 
(CnH2n+2),  with  a  sp.  gr.  of  about  72.  It  usually  contains  some  CGH6. 

It  is  unacted  upon  by  either  H2SO4  or  HNO3  (cold). 


Phenol  (Carbolic  Acid).    CelL.OH. 

Colourless  crystals  ;  becomes  pink  or  brown  on  exposure  to  air.  Strong 
characteristic  odour;  sparingly  sol.  in  cold  aq.,  readily  in  hot  aq.,  in 
spirit,  ether,  H2SO4,  KOH  and  NaOH.  Melts  41°  C.  ;  boils  181-5°  C. 

WET  TESTS. — Diss.  'i  gm.  in  8  c.c.  aq. 

FeCl8  '•  violet  colour,  destroyed  by  both  acids  and  alkalis. 

NH4OH  and  5  drops  of  bleaching  powder  sol.  or  Br  aq.,  warm  :  a  fine 
blue  colour. 

Pine  wood  soaked  in  HC1  and  moistened  with  phenol  becomes  pink  or 
purple,  exposure  to  light  deepens  the  colour.  (See  aniline.) 

Collodion  :  a  jelly. 

HN03  (cone.),  warm  :  bright  yellow  solution  of  picric  acid. 

Albumen  is  coagulated. 

Br  aq.  :  a  yellow  ppt.  of  tribromo-phenol,  C6H2Br3.OH. 

Liebermann's  reagent  (6  gm.  KNO2  in  100  gm.  of  H2SO4,  or  a  fragment 
of  KNO2  the  size  of  a  pin's  head,  dissolved  in  ^  c.c.  (cone.)  H2SO4),  gives  a 
blue  colour  with  strong  sols.;  when  poured  into  aq.  it  changes  to  red; 
alkalis  restore  the  blue  colour. 


VOLATILE   BASES. 


Aniline  (Phenylamine). 

Colourless  oily  liquid,  becomes  brown  on  exposure  to  the  air,  faint 
odour;  neutral  to  litmus.  Boils  183*7°  >*  burns  with  smoky  flame.  Slightly 
sol.  in  cold  aq.,  readily  sol.  in  alcohol,  ether  and  chloroform. 

Yields  crystallized  salts  with  acids.  KOH  and  NaOH  (but  not  NH4OH) 
decompose  the  salts  and  set  free  the  aniline. 

WET  TESTS. — Use  i  drop  of  aniline  from  the  end  of  a  glass  rod  for 
each  test. 

H2S04  (cone,)  :  solution,  on  long  boiling  becomes  brown ;  stir  a  dil.  sol. 
of  K2Cr2OT  (in  test  tube,  watch-glass  or  porcelain  basin)  with  a  glass  rod 
dipped  into  the  above  solution  :  blue  colour. 

The  following  tests  apply  to  both  the  base  and  its  salts. 

NaOH  in  alcohol  and  2  drops  of  chloroform,  warm  :  nauseous  odour  of 
carbylamine  (phenol  isocyanide). 

NaOCl,  or  bleaching  powder  solution  :  purple  colour.  Then  add  dil. 
NH4SH  :  magenta  colour,  fleeting. 

KClOs  (dil.)  to  dil.  aniline  sol.,  i  drop  to  5  c.c.  aq.,  then  run  a  little 
cone.  H2SO4  carefully  down  the  side  of  the  tube  :  a  violet  colour  rikg  at  the 
junction  of  the  liquids. 

Bromine  water  :  pinkish  ppt.  of  tri-bromaniline  (C6H2.Br3NH.2). 

Diazo  reaction.  Add  5  drops  of  KNO2  to  a  sol.  of  aniline  in  dil.  HC1 
cool  the  test  tube  under  the  tap,  next  add  a  few  drops  of  a  or  ft  naphthol  in 
NaOH  :  the  scarlet  colour  of  benz-azo-naphthol  (C6H5N:N.C10H6OH). 

Pyridine.     C5H5N. 

Colourless  oily  liquid,  with  strong  characteristic  odour.  Obtained  from 
bone  oil  and  the  distillatibn  of  alkaloids.  Fumes  with  volatile  acids  ; 
darkens  on  exposure.  Boils  116°;  sol.  in  aq.,  alcohol  and  ether.  A  strong 
base,  precipitates  Fe(OH)3,  A1(OH)3  etc.,  from  their  salts.  Yields  salts  with 
acids,  from  which  NaOH  and  KOH  set  free  the  pyridine. 

WET  TESTS. — Use  i  drop  of  pyridine  for  each  test. 

H2S04  (cone.)  :  white  ppt.,  dissolves  in  excess  to  a  colourless  sol. 

Br  aq.  in  excess  added  to  the  HC1  sol.  of  pyridine  :  yellow  ppt. 
(C6H5NBr2). 

H2PtCl6  and  HC1,  boil  and  cool  :  orange-yellow  ppt.  of  (CsH5N)2.H2PtCl(i. 

68 


QUINOUNE  69 

Quinoline.    C9H7N. 

Colourless,  limpid  liquid,  obtained  from  bone  oil  and  coal  tar;  with 
peculiar,  somewhat  aromatic  odour,  becomes  brown  on  exposure.  Boils 
238°.  Its  vapour  burns  with  a  luminous,  smoky  flame.  Sparingly  sol. 
in  aq.,  but  readily  in  many  organic  liquids.  A  strong  base,  yields 
deliquescent  salts.  It  precipitates  Fe(OH)3,  A1(OH)3,  etc.,  from  their  salts. 

WET  TESTS. — Use  i  drop  for  each  test. 

H2S04  (cone.)  :  crystals  of  sulphate,  soluble  in  excess. 

H2PtCl6  to  the  HC1  sol.  :  yellow  ppt.  of  (C9H7N).2H2PtCl6 ;  sol.  in  warm  aq. 

AgN03  on  shaking  :  white  ppt.  which  dissolves  on  warming,  but  re-forms 
on  cooling  ;  on  long  boiling  some  silver  is  reduced. 

K2Cr207  and  3  drops  of  HC1  :  ppt.  of  yellow  crystals  of  dichromate, 
(CyH7N).2H2Cr.2O7,  dissolves  on  warming.  (Distinction  from  pyridine.) 


ALKALOIDS. 


PRECIPITANTS. 

The  alkalis  and  alkali  carbonates  precipitate  many  of  the  alkaloids  from 
strong  sols,  of  their  salts. 

Platinum  Chloride  (Chloroplatinie  aeid),  H2PtClo,  forms  with  the  hydro- 
chlorides  of  the  alkaloids,  salts  similar  to  (NH4)2PtClc  in  which  the  NH4  is 
replaced  by  the  alkaloid ;  these  salts,  when  soluble,  are  most  readily 
formed  by  evaporating  H2PtClc  with  the  hydrochloride  of  the  alkaloid  over 
a  water-bath ;  extract  the  residue  with  alcohol. 

Solution  of  Iodine  in  KI  (deci-normal  sol.)  precipitates  the  alkaloids  as 
yellow  or  brown  polyiodides ;  to  convert  these  into  sulphates  evaporate  the 
well- washed  ppt.  to  dry  ness  with  H2SO4  over  a  W.B. 

Sols,  of  HgI2  in  KI,  of  CdI2  in  KI,  and  of  BiI3  in  KI  also  yield  ppts.  with 
the  alkaloids. 

'  Tannie  aeid  :  white,  yellowish  or  brownish  ppts. ;  the  alkaloid  can  be 
obtained  from  these  in  the  free  state  by  adding  KOH  and  taking  up  with 
ether,  amyl  alcohol,  benzene,  etc. 

Phospho-molybdie  aeid.  Gives  yellow  ppts.  with  alkaloids.  To  prepare 
it  boil  Am.  motybdate  with  Na2HPO4,  well  wash  the  ppt.,  diss.  in  warm 
Na2CO8,  evaporate  to  dryness,  ignite  ;  if  reduction  takes  place  (add  HNO3 
and  re-ignite)  warm  with  water  and  dissolve  in  a  large  excess  of  HNO3. 

Picric  acid.     Gives  yellow  ppts.  with  most  alkaloids. 


DIRECTIONS    FOR    APPLYING    THE    TESTS. 

COLOUR  TESTS. — Perform  the  colour  tests  on  a  glass  plate  over  white 
paper,  or  on  a  white  porcelain  slab ;  those  requiring  heat  should  be  done  on 
watch-glasses,  porcelain  crucible  lids,  or  clean  pieces  of  broken  dishes.  Use  i 
drop  of  the  reagent  and  a  small  quantity  of  the  alkaloid,  about  '2  mgm.,  or  a 
quantity  not  larger  than  the  size  of  a  pin's  head,  for  each  test,  unless  other- 
wise directed ;  for  liquids  use  i  drop  from  the  end  of  a  thin  glass  rod  about 
Y%  inch  thick.  Bring  the  reagent  and  substance  into  contact  with  a  pointed 
glass  rod. 

70 


CONIINE,  NICOTINE,  ATROPINE  AND  DATURINE  7 1 

VOLATILE  LIQUID  ALKALOIDS. 


Coniine.    CsHnN.    (Propyl  Piperidine). 

Colourless  oily  liquid,  becomes  brown  on  exposure,  with  offensive 
mouse-like  odour,  sol.  in  water,  alcohol,  etc.  ;  distils  in  steam ;  a  strong 
base. 

Dissolve  i  drop  in  5  drops  of  water. 

COLOUR  TESTS. — HJS04  :  colourless  sol.,  blackens  on  heating. 

H2S04  and  K^Cr^O?  :  green  colour. 

WET  TEST. — Alcohol,  add  2  drops  to  i  drop  of  a  solution  of  coniine,  in  an 
evaporating  dish,  then  2.  drops  CS..,  let  stand  3  minutes,  add  one  drop  of  dil. 
CuSO4  :  a  brown  colour.  (Distinction  from  nicotine.) 


Nicotine. 

Colourless  volatile  liquid,  with  strong  characteristic  odour,  turns  brown 
on  exposure.  Boils  at  250°  with  decomposition,  readily  distilled  in  steam. 
Readily  sol.  in  aq,,  alcohol  and  ether. 

TESTS. — The  odour  is  one  of  the  best  tests. 

Formaldehyde,  mix  2  drops  of  formalin  with  2  drops  of  a  10  per  cent, 
sol.  of  nicotine  on  porcelain,  then  add  2  drops  of  HNO3  :  pink  colour. 
(Distinction  from  Coniine.) 


NON-VOLATILE     SOLID    ALKALOIDS. 

(Arranged  in  alphabetical  order.) 


Atropine  and  Daturine  (Isomers). 

COLOUR  TESTS. — Divide  i  mgm.  into  3  parts. 

H-jS04  :  colourless  sol.,  brown  on  warming.  A  pleasant  odour  of  flowers 
when  heated  with  H2SO4  or  H2CrO4. 

HNO&  (fuming)  :  solution,  evaporate  to  dryness  over  W.B.,  and  add  i 
drop  of  alcoholic  KOH  to  the  colourless  residue  :  violet,  and  then  cherry-red 
colour. 

Ba  water,  evaporate  and  heat  strongly  :  odour  of  hawthorn 
blossom. 


72  BRUCINE    AND    CAFFEINE 

Brucine.    C23H26N204  4H20. 

Colourless,  right  rhombic  prisms  or  needles.  Sparingly  sol.  in  cold  aq., 
readily  sol.  in  alcohol,  amyl  alcohol,  chloroform,  but  less  in  benzene ;  nearly 
insol.  in  ether.  Its  salts  are  readily  sol.  in  water. 

Brucine  and  its  salts  are  very  bitter  and  poisonous. 

When  carefully  heated  it  loses  water  and  sublimes  unchanged. 

COLOUR  TESTS. — Divide  i  mgm.  of  brucine  nitrate  into  7  parts. 

H2S04  (cone.)  :  a  pale  rose  tint  becoming  yellow,  and  a  fleeting  red  if  a 
trace  of  HNO3  be  added  (characteristic). 

H2S04  and  solid  K2Cr207  :  red-brown  colour. 

HNOs  (cone.)  :  a  deep  red  colour,  yellow  on  warming  ;  drive  off  the  free 
HNO3  over  a  water  bath  and  add  a  drop  of  SnCL.  :  a  deep  purple  colour. 

Cl  water  :  a  fleeting  pink  or  red  colour,  turning  to  a  yellowish  brown  on 
addition  of  NH4OH. 

Erdmann's  reagent  (see  index)  :  pale  red  changing  to  yellow  or  orange. 

Mandelin's  reagent  (see  index)  :  rose  colour,  rapidly  changing  to  orange. 

Hg(NO»>2  (free  from  acid)  :  colourless  sol.,  warmed  on  a  water  bath  :  car- 
mine. (Distinction  from  strychnine.) 

PRECIPITANTS. — Diss.  i  mgm.  of  brucine  nitrate  in  3  c.c.  of  aq. 
The  alkalis  and  their  carbonates  precipitate  brucine  from  its  salts. 

NH4OH  :  ppt.  sol.  in  excess,  but  it  slowly  crystallizes  out  on  standing. 

KCNS  :  white  ppt.  sol.  in  excess. 


Caffeine  (Theine).    C8HioN402. 

Silky  needles,  bitter  taste;  sol.  in  alcohol  and  ether.  Melts  232°. 
Sublimes  unchanged  ;  a  weak  base. 

DRY  TEST. — Soda  lime,  heat  :  NH3  evolved ;  carbonate  and  cyanide 
left ;  test  for  cyanide  by  HC1  and  Fe  salts. 

COLOUR  TESTS. — Divide  i  mgm.  into  4  parts. 

H.2S04  (cone.),  and  dry  K2Cr207  :  a  green  colour  slowly  appears. 

HNO:i,  evaporate  to  dry  ness  :  a  yellow-red  stain  ;  cool  and  add  NH4OH  : 
purple  (murexide). 

Br  water,  dry  on  W.B.  :  yellow  to  crimson  residue,  add  NH4OH  : 
purple  (murexide). 

Mayer's  reagent  (see  index),  no  change.  (Distinction  from  other 
alkaloids.) 

WET  TEST. — NaOH,  boil  :  fish-like  odour  of  methylamine. 


CINCHONINK,    COCAINE   AND   CODEINE.  73 

Cinchonine.    CiglLzNCk 

Crystallizes  in  lustrous  prisms.  Sparingly  sol.  in  aq.,  more  sol.  in 
alcohol,  atnyl  alcohol,  ether  and  chloroform.  Bitter  taste.  Melts  255°  to  a 
colourless  fluid. 

DRY  TEST. — If  cautiously  heated  in  a  dry  tube  it  sublimes  unchanged. 

COLOUR    TESTS. — Divide  i  mgm.  into  3  parts. 

H2S04  (cone.)  :  colourless   sol.  ;    warm  :  brown  to   black. 

HC1,  and  evaporate  to  dry  ness  :  purple  colour  and  purple  vapours,  the 
same  as  quinine  and  quinidine.  » 

Mandelin's  reagent  :  same  as  quinine  and  quinidine. 

PRECIPITANTS. — Diss.  i  mgm.  cinchonine  sulphate  in  3  c.c.  aq.  This 
sol.  is  not  fluorescent. 

NaOH,  KOH,  NH4OH  and  their  carbonates  :  precipitates  of  amorphous 
cinchonine  from  its  salts. 

Cl  water,  5  drops,  and  5  drops  NH4OH  :  yellowish  ppt. 

K4FeCy6  :  flocculent  ppt.  of  cinchonine  ferrocyanide,  sol.  in  excess  of 
K4FeCy6  on  warming  ,  on  cooling  it  crystallizes  out  in  brilliant  yellow  scales 
or  needles. 


Cocaine  (Methyl-benzoyl-ecgonine). 

Colourless  prisms.  Melts  98° ;  sublimes  at  higher  temps.  Readily  sol. 
in  alcohol,  ether,  chloroform,  benzene,  and  petroleum ;  sparingly  in  water. 
Its  salts  are  readily  sol.  in  water. 

COLOUR  TESTS. — Divide  i  mgm.  of  cocaine  hydrochloride  into  3  parts. 

H2S04  :  no  colour,  add  a  particle  of  K2Cr.2O7  :  brown  colour. 

KMn04  (strong  sol.),  add  to  alcohol  sol.  in  watch-glass  :  purple  ppt.  of 
cocaine  permanganate. 

K2Cr207  and  2  drops  HC1,  on  watch-glass  :  light  yellow  ppt.  (charac- 
teristic). 

WET  TESTS. — Diss.  i  mgm.  cocaine  hydrochloride  in  2.  c.c.  aq. 

H2S04  (cone.),  warm  :  odour  of  benzoic  acid  ;  add  2  c.c.  alcohol,  boil  : 
odour  of  ethyl  benzoate. 

FeCls,  one  drop,  boil  :  red-brown  colour. 


Codeine  (Methyl  morphine)      Ci7Hi7NO(OCH3)OH. 

Crystallizes  in  orthorhombic  prisms.  Melts  at  150°.  Moderately  sol. 
in  hot  aq.  ;  readily  sol.  in  alcohol,  atnyl  alcohol,  ether,  chloroform  and 
benzene.  Alkaline  reaction. 


74  MORPHINE     AND     NARCOTINE 

COLOUR  TESTS. — Divide  i  mgm.  into  5  parts. 

H2S04  :  colourless  sol.  ;   blue  when  warmed  ;    (a)  add  FeCl3  to  cold  sol. 
deep  blue  ;  (b)  grind  with  sugar  :  purple-red  on  standing. 
HN0.5  :  a  yellow  colour. 

Froehde's  reagent  :  green  and  finally  blue  sol. 
Cl  water  :  dissolves ;   add  NH4OH  :  orange. 
Moisten  with  formalin,  add  2  drops  cone.  H.2SO4  :  violet  colour. 


Morphine.     Cn 

Crystallizes  in  colourless  prisms,  sol.  in  alcohol  and  amyl  alcohol,  almost 
insol.  in  cold  aq.,  ether,  chloroform  and  benzene  ;  sparingly  sol.  in  hot  aq., 
poisonous. 

COLOUR  TESTS. — Divide  i  mgm.  of  morphine  hydrochloride  into  8  parts. 

H-.SOi  :  pale  rose  colour  ;  warm  :  violet  and  then  brown,  add  a  trace  of 
HNO3  and  warm  :  red  colour. 

H2S04  and  a  particle  of  KaCr^O?  :  dull  green  colour. 

H2S04  (cone.)  2  drops,  and  a  fragment  of  FeSO4,  warm  on  a  W.B.  for  one 
minute,  stir,  cool,  add  excess  of  NH4OH  :  pink,  then  red  and  violet. 
(Distinction  from  codeine.) 

Formalin,  i  drop,  and  2  drops  cone.  H.2SO4  :  deep  purple  colour. 

HNO.j  :  bright  orange  colour. 

FeCl*  (neutral)  :  an  indigo  blue  colour  with  strong  sols,  of  morphine 
salts. 

Froehde's  reagent  :  violet,  changing  to  green. 

lodie  acid,  one  drop  :  free  iodine. 

PRECIPITANTS. — Diss.  i  mgm.  of  morphine  hydrochloride  in  2  c.c.  aq. 

NaOH,  KOH,  NH4OH  and  their  carbonates  :  ppt.  of  morphine,  readily  sol. 
in  an  excess. 


Narcotine.     Cs 

Colourless  lustrous  prisms  or  needles.      A  weak  base. 
COLOUR  TESTS. — Divide  i  mgm.  into  4  parts. 

H2S04  (cone.)  :  yellow  solution  changing  to  red  and  dusky  violet  when 
warmed  slowly  on  a  water  bath.      FeCl3  restores  the  red  colour. 
H2S04  (cone),  and  dry  K2Cr207  :  rich  brown  colour. 
HN03  :  yellow  solution,  orange  on  warming. 
Froehde's  solution  :  green  sol.  ;  warm  :  red. 


PAPAVERINK    AND    QUININE  75 

PRECIPITANTS. — Diss.  i  rngm.  narcotine  in  2  c.c.  dil.  HC1. 

Cl  water  :  greenish  yellow  ;  add  NH4OH  :  orange  (only  from  strong 
sols.). 

Br  water  added  drop  by  drop  to  the  HC1  sol.  :  yellow  ppt.  ;  boiled  :  red 
colour.  Destroyed  by  slight  excess  of  Br. 


Papaverine. 

Crystallized  in  prisms,  feebly  alkaline,  not  poisonous,  soluble  in  hot 
alcohol,  crystallizes  on  cooling  ;  insol.  in  water. 

COLOUR  TESTS. — Divide  i  mgm.  into  3  parts. 

H2S04  :  colourless  or  yellow  solution  becoming  violet  on  warming. 

Froehde's  reagent  :  green  through  blue  to  violet  colour,  and  cherry 
red. 

Cl  water  and  NH4OH  :  red-brown  colour,  turning  to  very  dark  brown. 

Iodine  solution  (with  strong  sol.)  :  dark  red,  then  brick-red  and  dark  red 
again. 


Quinine.     C2<,H24N202,3H20. 

Crystallized;  slightly  sol.  in  cold  aq.,  more  soluble  in  hot  water  and 
NH4OH,  in  alcohol,  chloroform,  ether,  petroleum,  and  benzene.  Bitter 
taste ;  turns  litmus  blue.  Solutions  of  quinine  salts,  especially  of  the 
sulphate  and  other  oxidized  acids,  exhibit  a  strongly  marked  blue 
fluorescence. 

COLOUR  TESTS. — Divide  i  mgm  of  quinine  sulphate  into  3  parts. 

H2S04  (cone.)  :  colourless  solution,  add  particle  of  K2Cr2O7  :  grass 
green. 

HC1  (cone.)  evaporate  to  dryness  in  porcelain  dish  :  a  violet  colour  just 
before  it  chars,  and  violet  vapours,  like  iodine,  are  evolved. 

Mandelin's  reagent  :  no  change  :  add  one  drop  HNO3  :  violet. 

PRECIPITANTS. — Diss.  i  mgm.  quinine  sulphate  in  2  c.c.  aq. 

Ammonia,  alkalis,  and  their  carbonates  :  ppt.  of  amorphous  quinine 
from  strong  sols.,  which  gradually  becomes  crystalline. 

Cl  water  and  an  excess  of  NH4OH  :  a  green  colour.  Add  3  drops  of 
esh  K3FeCyfi  sol.  to  this  :  bright  red. 


76  STRYCHNINE    AND   VERATRINE 

Strychnine.    CaiH^NaCk 

Strychnine  and  all  its  salts  are  virulent  poisons.  Crystallizes  in  white 
rhombic  prisms.  Readily  soluble  in  hot  chloroform  ;  very  sparingly  sol.  in 
hot  water  (i  in  2500),  benzene,  amyl  alcohol,  absolute  alcohol  and  ether  ; 
slightly  sol.  in  dil.  alcohol.  Its  salts  are  sol.  in  aq.  and  in  alcohol,  but 
insol.  in  ether,  chloroform,  amyl  alcohol  and  benzene ;  all  have  a  bitter 
taste,  i  part  in  700,000  of  aq.  can  thus  be  recognised. 

COLOUR  TESTS. — Divide  i  mgm.  of  strychnine  sulphate  into  3  equal 
parts. 

H2S04  (cone.),  and  a  fragment  of  either  K2Cr207,  Mn02,  Pb02,  or  K3FeCyfi  : 
beautiful  purple  colour  changing  to  red  and  green. 

NOTE. — This  test  does  not  answer  with  St.  nitrate,  nor  with  the 
sulphate  in  the  presence  of  antipyrine.  Strychnine  is  often  added  to  anti- 
pyrine  for  medicinal  purposes. 

HN03  (cone.)  :  colourless  sol.,   yellow  when  warmed. 

Mandelin's  reagent  :  blue  colour  changing  to  violet ;  NH4OH  changes  it 
to  rose  colour.  Characteristic. 

PRECIPITANTS. — Diss.   i  mgm.  of  strychnine  sulphate  in  4  c.c.  aq. 

KOH  and  NaOH  and  their  carbonates  give  with  St.  salts,  white  crystalline 
ppts.  The  ppt.  with  NH4OH  is  sol.  in  an  excess,  but  gradually  crystallizes 
out  in  needles. 

Cl  water  :  white  ppt.,  sol.  in  excess. 

Iodine  (strong  sol.  in  KI)  :  reddish  brown  ppt. 

KCNS  :  a  white  ppt.  insol.  in  excess ;  slowly  formed  in  dil.  sols. 


Veratrine. 

Amorphous,  white  or  grey,  crystallizes  from  alcohol,  No  odour,  but 
causes  violent  sneezing.  Sol.  in  CHC18  and  alcohol,  sparingly  in  ether 
and  amyl  alcohol. 

COLOUR  TESTS. — Divide  i  mgm.  into  7  equal  parts. 

H2S04  :  yellow  solution,  red  when  heated. 

HN03  :  pale  yellow  to  green. 

HC1  (cone.)  :  colourless  sol.  ;  boil  :  red  colour. 

Erdmann's  reagent  :  yellow  to  deep  red. 

Mandelin's  reagent  :  dusky  yellow  to  crimson. 

Froehde's  reagent  :  yellow,  becoming  cherry-red  on  standing. 

When  rubbed  with  3  times  as  much  cane  sugar  and  H2SO4  (2  drops) 
it  becomes  yellow  (green  by  reflected  light)  and  finally  indigo  blue. 


ACETANILIDE,  ANTIPYRINE  AND  PHENACETIN  77 

ARTIFICIAL  ALKALOIDS. 


Acetanilide  (Antifebrin).     CsIL.NH.COCIL. 

Crystallizes  in  colourless  lustrous  plates.  Melts  113°.  Readily  soluble 
in  alcohol,  ether,  chloroform  and  boiling  aq. 

COLOUR  TESTS. — 

H2S04  (cone.),  stir  with  a  little  powdered  K2Cr2O7  :  red  streaks,  quickly 
turning  green. 

Mandelin's  reagent  :  orange  red  ;  this  becomes  red  and  then  grey. 

Hg2N03,  2  drops,  on  slow  evaporation  :  green  residue ;  stir  this  with  a 
little  cone.  H2SO4  :  deep  red. 

WET  TESTS. — Diss  'i  mgm.  in  3  c.c.  of  alcohol. 

FeCl3,  boil,  becomes  turbid  and  darker  in  colour.  (See  antipyrine  and 
phenacetin.) 

KOH,  warm  :  K  acetate  and  aniline.  Test  for  the  aniline  by  warming 
with  2  drops  of  CHC13  :  odour  of  carbylamine  ;  or  dilute  with  aq.,  shake  up 
with  ether,  separate  the  ethereal  sol.  and  test  it  for  aniline  ;  test  the  water 
sol.  for  acetic  acid. 

H2S04  (cone),  and  alcohol,  warm  :  odour  of  ethyl  acetate. 


Antipyrine  (Phenazone).     Cn 

Colourless,  odourless  crystals.  Melts  114°.  Bitter  taste,  neutral  re- 
action, yields  salts.  Soluble  in  water  and  in  alcohol,  sparingly  in  ether. 

DRY  TEST. — Heated  in  a  dry  tube  :  melts  and  chars,  a  brown  liquid 
condenses. 

COLOUR  TESTS. — Divide  i  mgm.  into  6  parts. 

H2S04  (cone.),  warm  :  colourless. 

HNO.s  (cone.),  warm  :  yellow  to  red  colour. 

HgCl2  :  white  ppt. ,  dissolves  on  warming  ;  re-formed  on  cooling. 

KN02,  fragment,  and  2  drops  dil.  H2S04  :  bright  reddish-yellow  colour 
(isonitroso-antipyrine).  Strong  sols,  of  antipyrine  yield  green  crystals. 

Mandelin's  reagent  :  pale  blue  colour,  evanescent. 

FeCl3,  warm  :  deep  red  colour. 


Phenacetin   (para-acetamido-ethoxybenzene).       C2H5O.C6H4.NH.COCH3. 

Colourless,  odourless,  crystalline  scales.       Melts  135°.     Almost  insol.  in 
cold  aq.,  fairly  sol.  in  hot  water  and  readily  sol.  in  ether  and  chloroform. 


78  DETECTION   OF   SINGLE   ALKALOIDS 

DRY  TESTS. — Heat  in  a  dry  tube  :  melts  and  sublimes. 

Mix  with  twice  its  bulk  of  zinc  dust  or  filings,  and  heat  to  charring; 
cool,  boil  with  a  little  water,  filter,  add  FeCl3  :  violet  colour,  due  to  the 
salicylic  acid  formed. 

COLOUR  TESTS. — Use  i  mgm.  divided  into  2  parts. 

HN03  (i  to  i  aq.)  warm-:  orange  colour,  and  yellow  crystals  on  cooling. 
Add  KOH  in  excess  :  red  colour,  which  deepens  on  boiling. 

KN02,  grind  with  an  equal  bulk  of  phenacetin,  mix  with  2  drops  cone. 
H2SO4  and  warm  on  a  water-bath  :  green  colour. 

WET  TESTS. — Diss.  i  mgm.  in  2  c.c.  aq. 

FeCl3  (dil.  sol.)  warm  :  red  colour. 

H2S04  (cone.)  and  alcohol,  warm  :  odour  of  ethyl  acetate. 


DETECTION  OF  SINGLE  ALKALOIDS. 

1.  Heated  on  Pt  foil  :  nitrogenous  odour  and  smoky  flame. 

2.  Heated  with  soda-lime  :  odour  of  NH3. 

3.  Placed  on  litmus  paper  and  moistened  with  alcohol,  a  blue  colour  :  a 
free  alkaloid. 

The  solution  of  the  salt  of  the  alkaloid  must  not  be  too  dilute,   and 
must  be  free  from  substances  which  would  interfere  with  the  tests. 


GROUP  I. — ATROPINE,  (ANILINE)..  CONIINE,  NICOTINE  AND   MORPHINE. 

Add  KOH  to  the  sol.  until  it  is  just  alkaline  ;  stir  briskly  and  allow  to 
stand. 

a.  No  ppt.  ;   (i).   Heat  with  H2SO4  or  H2CrO4 ;  a  characteristic  pleasant 
odour    of    flowers.       (2)  Iodine    is   not   separated   on    addition    of   HIO3  : 
atropine. 

b.  A  disagreeable  odour  is  evolved  and  oily  drops   separate  :  (aniline), 
nicotine,  eoniine. 

Extract  with  ether  and  evaporate  the  ethereal  extract  to  dryness  with 
HC1:— 

An  amorphous  residue  :  nicotine  hydroehloride. 

A  crystalline  residue  ;  when  boiled  with  HNO3  becomes  red,  violet, 
green,  blue,  and  finally  brown,  especially  if  free  acid  be  present  :  eoniine. 

c.  A  ppt.  sol.  in  excess  :  morphine  or  atropine. 
Confirm. — Add  iodie  acid, 

Iodine  is  not  separated  :  atropine. 


DETECTION   OF   SINGLE   ALKALOIDS  79 

Iodine  separates  out  :  morphine. 

FeCls  neutral  (dil.)  :  a  blue  or  green  colour,  if  the  sol.  be  concentrated 
and  neutral  :  morphine. 

GROUP   II. — ClNCHONINE,    NARCOTINE   AND    QUININE. 

Add  2  drops  dil.  H2S04  and  just  neutralise  with  a  saturated  solution  of 
NaHCO3,  stir  well  and  allow  to  stand  30  minutes. 

A  precipitate  :  einehonine,  nareotine  or  quinine. 

Heat  cautiously  :  fuses  and  yields  a  sublimate  of  white  needles  : 
einehonine. 

NHiOH  in  excess,  and  shake  with  ether,  (a)  the  ppt.  does  not  dissolve  : 
einehonine  ;  (b)  it  dissolves  :  nareotine  or  quinine. 

K4FeCy6  to  a  neutral  sol.  :  a  white  ppt.  sol.  in  excess ;  warm,  bright 
yellow  crystals  separate  out  on  cooling  :  einehonine. 

Cl  water  and  2  drops  of  NH4OH,  (a)  a  deep  red  solution  :  nareotine  ;  (b)  a 
green  or  blue  sol.  :  quinine. 

GROUP  III. — BRUCINE,  CAFFEINE,  COCAINE,  CODEINE,  DIGITALIN, 
PAPAVERINE,  PICROTOXIN,   QUININE,   SAUCIN,  STRYCHNINE, 

VERATRINE. 

If  the  substance  be  liquid,  evaporate  to  dryness  on  a  watch-glass  and 
stir  the  residue  with  a  glass  rod  dipped  in  cone.  H.>SO4. 

a.  A  rose  colour  becoming  intensely  red  on  addition  of  HNO3  :  brueine. 
Confirm  (i)    Cl  water  (the  gas  is  better)  :  red.     NH4OH  changes  this  to 

yellowish  brown  ;  (2)  HNO3  gives  blood  red,  then  yellow,  changed  to  violet 
on  addition  of  SnCL. 

b.  A  yellowish  colour,   becoming   orange    red     and    finally    crimson  on 
heating  :  veratrine.     Confirm.     Mix  with    3   times   its  bulk  of  cane  sugar 
and  moisten  with  strong  H2SO4  :  reddish  brown,  gradually  turning  to  blue. 

c.  Colourless   or   faint  yellow   on   standing-  :  caffeine,  cocaine,  codeine, 
papaverine,  quinine  and  strychnine. 

Confirm  for  caffeine. — HNO3,  dry  on  W.B.,  add  NH4OH  :  purple  colour 
(murexide).  Confirm  for  cocaine. — K.2Cr.2O7  and  2.  drops  of  HC1  :  light 
yellow  ppt.  Confirm  for  codeine. — H2SO4  and  FeCl3  :  deep  blue  colour. 
Confirm  for  papaverine. — Iodine  solution  :  dark  red.  Confirm  for  quinine. — 
(i).  Fluorescence  in  solutions  of  its  salts;  (2)  Cl  water  and  then  NH4OH  : 
green.  Confirm  for  strychnine. — (i)  KCNS  :  white  crystalline  ppt.  ;  (2}  a 
bitter  taste  in  very  dil.  solutions ;  (3)  cone.  H2SO4  and  solid  K.2Cr.2O7  :  deep 
blue  colour  changing  to  wine  red. 

d.  A  reddish-brown  colour. 


80  DETECTION    OF   SINGLE   ALKALOIDS 

BP  water,  the  reddish-brown  colour  changes  to  purple  :  digitalin. 
Confirm.— Warm  the  solution  in  water  with  phospho-molybdic  acid  :  bright 
green,  which  changes  to  blue  on  adding  NH4OH  :  digitalin. 

e.  A  saffron  colour,    add  K2Cr207  (powder)   a   violet     or    brown    colour 
changing  to  blue  :  pierotoxin.     Confirm. — (i)    Moisten  the   substance   with 
HNO3,  dry  on  water  bath  and  stir  with  a   rod  dipped  in   H.2SO4,   then  mix 
with  excess  of  KOH  :   orange  colour  ;   (2)  add  Fehling's  solution,  warm, 
ppt.  of  Cu.2O  :  pierotoxin. 

f.  A  blood-red  colour  :  saliein.     Confirm. — (i)    FeCl3   :  a    pale    brown, 
colourless   on  boiling    and    a  dull  yellow    ppt.  ;     (2)    AgNO3,    warm,    add 
excess  of  NH4OH  and  NaOH,  a  mirror  of  reduced  Ag  :  saliein. 

NOTE. — Digitalin,  Pierotoxin  and  Saliein  are  not  alkaloids,  but  resemble 
them  physiologically. 


TABLES 

FOR 

QUALITATIVE    CHEMICAL    ANALYSIS. 


PRELIMINARY     EXAMINATION. 

LIQUIDS. — If  the  substance  be  a  liquid,  examine  its  reaction  with  litmus 
paper  : — 

It  is  neutral. — Free  acids,  acid  salts  and  the  majority  of  the  normal 
salts  of  the  heavy  metals  must  be  absent. 

It  is  acid. — Either  free  acids,  acid  salts  or  normal  salts  having  an  acid 
reaction,  may  be  present. 

It  is  alkaline. — Salts  possessing  an  alkaline  reaction,  free  alkalis,  alka- 
line earths  or  their  borates,  carbonates,  cyanides,  silicates,  phosphates  or 
sulphides  may  be  present. 

Evaporate  a  portion  of  the  liquid  in  a  watch-glass  or  on  a  piece  of 
platinum  foil.  If  it  does  not  leave  a  residue  the  liquid  may  be  water  only ; 
if  a  residue  be  left,  evaporate  a  larger  quantity  in  a  porcelain  dish.  The 
residue  should  be  examined  and  described  as  to  colour,  crystalline  form,  etc., 
and  then  submitted  to  the  preliminary  tests  as  laid  down  for  solids. 

SOLIDS. — Examine  the  substance  carefully  for  traces  of  crystalline  form 
or  structure,  .note  down  the  colour,  lustre,  degree  of  transparency,  hardness, 
density,  i.e.,  whether  it  has  a  light  or  heavy  feel ;  the  odour,  if  any  ;  also  the 
feel  when  rubbed  between  the  fingers ;  and  ascertain  whether  it  is 
attracted  by  a  magnet. 

PRELIMINARY    TESTS. 

The  substance  must  first  be  ground  down  to  the  finest  powder  possible, 
unless  it  be  already  in  that  state. 

When  several  substances  are  present  together  in  a  mixture,  the  results 
obtained  may  not  be  exactly  as  they  are  here  stated,  since  one  reaction  often 
masks  or  obscures  another. 


Experiment  J.— Heat  some  of  the  powder  in  an  ignition  tube,  i.e.,  in 
a  piece  of  hard  glass  tubing  about  2  inches  long  by  ^  inch  wide,  and  closed  at 
one  end. 

81 


82 


TABLES   FOR    QUALITATIVE    CHEMICAL   ANALYSIS 


Inferences. 


1.  The  substance  does  not  change. 


2.  It  decrepitates. 

3.  It  changes  colour  without  fusing. 

Cold.  I  Hot. 


Absence  of  organic  mat- 
ter, moisture,  combined 
water  and  salts  of  NH4, 
Hg,  As,  etc. 

Presence  of  nitrates,  chlor- 
ates, sodium  chloride,  etc. 


White. 

Yellow. 

ZnO. 

White  or  yellow. 

Yellowish  brown. 

SnO,,  TiO2. 

Red-brown. 

Dark  red. 

Fe,03. 

Red. 

Black  ;  Hg  globules 

HgO. 

4.  It  changes  colour  and  fuses. 

Yellow. 

Yellow  or  red-brown 

PbO. 

White  or  yellow. 

Orange  or  brown. 

Bi2O8. 

Yellow. 

Dark  red. 

K,CrO4. 

Red. 

Black. 

Pb;A. 

5.  The  substance  chars  and  evolves  empyreu- 

matie  odours  and  decomposition  products. 

Chars  readily,  smell  of  burnt  feathers. 

A  smell  of  burnt  sugar  (caramel)  is  given 
off,  afterwards  becoming  pungent. 

Chars  slightly,  acetone  is  evolved. 

The    residue   contains   a  soluble  alkaline 
carbonate. 

The    residual    carbonate   is    insoluble    in 
water. 

6.  It  does  not  change  colour. 


7.  Fumes  are  evolved  and  a  sublimate  is  formed. 


(a)  It  sublimes  without  fusing. 

The  sublimate  is  white. 

The  sublimate  is  yellow  when  hot,   white 
when  cold. 


Presence  of  organic  matter. 

Urates,  alkaloids  and  pro- 
teids. 

From  sugar,  tartrates,  cit- 
rates, malates,  tannates, 
gallates,  etc. 

From  acetates. 

Organic  compounds  of 
NaOH,  KOH,  etc. 

Organic  salts  of  the  alkaline 
earths,  etc. ' 

Most  salts  of  the  alkalis, 
certain  salts  of  the  alka- 
line earths,  as  chlorides 
and  nitrates. 

Compounds  of  NH4,  Hg, 
As,  Sb,  also  S,  I,  SnCl, 
and  CdCl,.  PbCL  sub- 
lin^es  at  a  high  tempera- 
ture. Oxalic,  benzoic 
and  succinic  acids. 

NH4  salts. 
Hg2Cl,. 


TABLES    FOR    QUALITATIVE    CHEMICAL   ANALYSIS 


Results. 


Inference 


A  sublimate  of  white  octahedral  crystals. 
White  quadrilateral  prisms. 

(b)  The  substance  fuses  and  yields  a  tvhite 

sublimate. 

Melts  readily  and  evolves  heavy  fumes  ; 
white  crystalline  sublimate. 

Fuses,  changes  to  yellow ;  at  a  red  heat  : 
sublimate  of  white  acicular  crystals. 

At  a  high  temperature  :  a  dark  yellow 
fluid  sublimate 

Bright  scales  sublime  ;  fuses  to  a  reddish- 
yellow  liquid  at  a  high  temperature. 

White  scales  and  odour  of  frankincense. 
Silky  needles  and  irritating  fumes. 
White  fumes  and  white  crystals. 
White  amorphous  sublimate. 

(c)  The  sublimate  is  yellow. 

Yellow  and  red  sublimate  and  green  flame 
at  mouth  of  tube. 

Reddish-brown  drops,  yellow  when  cold. 

(d)  The  sublimate  is  blue   or  Mack. 

Blue. 

Dull  black,  red  when  rubbed. 

Violet  vapours  are  evolved  and  a  metallic- 
looking  blue-black  cr}7stalline  sub- 
limate is  formed. 

Confirm  for  Hg,  As  aiud  Cd  by  heating 
some  of  the  dry  substance  in  an 
ignition  tube  with  Na2CO»  and  a  little 
charcoal  powder. 

Metallic  globules  or  mirror. 

A  black  metallic  mirror. 

A  metallic  mirror  and  brown  sublimate. 

8.  The  substance  readily  fuses   and  gives   off 
moisture. 

The  moisture  turns  red  litmus  paper  blue. 
The  moisture  reddens  blue  litmus  paper. 


It  also  intumesces  or  swells  up. 


As.,O3. 
Se02. 


HgCla. 
Sb2O3. 

PbCla. 

MoO3. 

Benzole  acid. 
Succinic  acid. 
Oxalic  acid. 
Te02. 

P. 

S  and  polysulphides. 

Indigo. 

HgS. 

I.     (lodoform,  etc.) 


Hg. 

As. 
Cd. 

Certain  hydroxides  and  hy 
drates. 

NH4  compounds. 

Free  acids,  such  as  HC1, 
HN03,  H,S03,  H8SO<, 
etc. ,  or  of  acid  salts. 

Salts  with  water  of  crystal- 
lization, e.g., alums,  phos- 
phates, borates,  etc. 


84 


TABLES    FOR    QUALITATIVE   CHEMICAL  ANALYSIS 


Results. 


Inference. 


9.    (a).  The   substance  gives   off  a   colourless, 
odourless  gas. 

The  gas  re-inflames  the  glowing  end  of  a 
match. 


It  supports  combustion. 


The  gas  does  not  support  combustion. 


The  gas  does  not  support  combustion. 
Dip  a  glass  rod  into  lime-water  and 
lower  it  into  the  test  tube  ;  the  lime- 
water  becomes  turbid. 

Pass  the  gases  through  Ca(OH)2  sol.  The 
issuing  gas  burns  with  a  blue  flame. 


)  The  gas  possesses  odour. 

The   gas   smells   of  NH3   and   turns  red 
litmus  paper  blue. 


Confirm  for  NH3  by  warming  the  substance 
in  a  test  tube  with  KOH  solution. 

Smells  like  stale  eggs  and  blackens  paper 
moistened  with  lead  acetate. 


A   gas    with   a  suffocating   odour    which 
reddens  blue  litmus  paper. 


Confirm  for  SO2  by  lowering  a  rod  mois- 
tened with  K2CrO4  into  the  test  tube, 
a  green  colour  :  SO2. 

A  gas  with  garlic  odour,  burns  with  a 
green  flame. 

A  fetid  smell  of  CS2. 

The  odour  of  bitter  almonds,  and  burns 
with  a  peach-coloured  flame. 


Oxygen  from  peroxides, 
chlorates,  perchlo  rates, 
nitrates,  bromates,  and 
i  o  d  a  t  e  s  ;  N»O  from 
NH4NO3. 

N,O  from  NH4NO;,,  or  a 
nitrate  in  the  presence  of 
an  ammonium  salt. 

N  from  NH4NO2,  or  a 
nitrite  in  the  presence  of 
an  ammonium  salt. 

Carbonates  ;  oxalic,  benzoic 
and  succinic  acids,  etc. 


CO  and  CO2  from  the  de- 
composition of  oxalic 
acid,  oxalates,  and  form- 
ates. 


Ammonium  salts  ;  from  the 
cyanates  in  the  presence 
of  H.2O  and  from  nitro- 
genous organic  matter. 


SHa  from  hydrated  sul- 
phides and  hyposulphites 
in  the  presence  of  moist- 
ure. 

SO2  from  sulphites  ;  or  hy- 
posulphites, sulphates 
and  from  metallic  sul- 
phides and  thiocyanates. 


PH3  from  phosphites  and 
hypophosphites. 

Certain  thiocyanates. 

Cy  from  cyanides  of  Ag, 
Hg,  Cu,  Zn,  and  from  cy- 
anates and  thiocyanates. 


TABLES   FOR 


f\ 

QUALITATIVE 

Ti 


CHEMICAL    ANALYSIS 


Results. 


Inference. 


Confirm  for  Cy,  when  CO2  is  also  present, 
by  passing  the  gases  through  lime- 
water  and  igniting  the  Cy. 

(c)   It  gives  off  a  coloured  gas.  f 

Brown  fumes  of  N2O4  mixed  with  oxygen. 

A  yellow-green  gas  with  peculiar  smell ; 
bleaches  litmus,  and  turns  KI  and 
starch  paper  blue. 

Brown  fumes  with  peculiar  odour. 
Brown  fumes  condensing  to  red  liquid. 
Purple  vapours  and  sublimate. 

A  vapour  condensing  to  yellow  or  brown 
drops  and  burning  with  a  blue  flame. 

White  fumes  of  HC1  or  SO,. 


Nitrates  of  the  heavy  metals, 
such  al"Pb,  Bi,  etc. 

Cl,  from  chlorides  of  Pt,  Au, 
etc.,  also  from  certain 
chlorates  and  h  y  p  o- 
chlorites. 

Br  from  bromides  and  some 
bromates. 

Chromyl  chloride,  from 
chloride  and  chromate. 

I  from  iodides  and  some 
iodates. 

S,  from  certain  metallic  per- 
sulphides,  as  PtS2,  Au2S3, 
Sb2S5,  SnS2,  FeS2,  etc. 

From  certain  chlorides  and 
sulphates. 


Experiment  II.—  Heat  a  little  of  the  substance  on  charcoal  before  the  .» 
blowpipe,  in  the  outer  flame. 


Results. 


Inferences. 


\.  The  substance  decrepitates. 
2.  It  deflagrates. 


3.  It  fuses  readily  and  is  absorbed  by  the  char- 
coal or  forms  a  fluid  bead. 


4.  An   infusible    white    residue    is    left,    very 
luminous  when  strongly  heated. 

The  residue  turns  moistened    red   litmus 
paper  blue. 


NaCl,  KNO3,  Pb2NO8>  etc. 

Nitrates,  chlorates,  bro- 
mates and  iodates. 

Alkali  salts  and  certain 
salts  of  the  alkaline 
earths. 

BaO,  SrO,  CaO,  MgO, 
A12O3,  ZnO  and  SiO2. 
Also  ZrO2,  ThO,,  etc. 

BaO,  SrO,  CaO,  MgO. 


86 


TABLES    FOR    QUALITATIVE  WKMICAL   ANALYSIS 


Experiment  III.—  When   the   white  infusible  residue   is  cold,   add   a 
drop  of  Co2N03  and  again  ignite  strongly. 


Results. 


Inferences \ 


A  blue  coloured  mass  is  left. 


A  pale  pink-coloured  mass  is  left. 
A  bluish  gree^i-coloured  mass  is  left. 
A  pale  green-coloured  mass  is  left. 
A  violet-coloured  mass  is  left. 


A12OS,    phosphates    of    Ca, 
Sr    and    Ba    and    many 
silicates. 
MgO. 
SnO., 

ZnO,    Ti(X 
Phosphate      of     magnesia, 

Mg8(P04)2. 
5.  A  coloured  residue  is  left. 

The  residue  is  black. 

And  is  attracted  by  the  point  of  a  mag- 
netised pen-knife  blade.* 

Confirm. — Transfer  the  particles  to  a  piece  of  filter  paper  laid  on  glass, 
add  a  drop  of  dil.  HC1  and  of  HNO3.  Dry  carefully  over  a  flame  ;  a  pale 
pink  tint  which  turns  to  blue  :  Co.  A  greenish  tint  changing  to  yellow  :  Ni. 
Add  a  drop  of  K4FeCy(i,  a  blue  colour  :  Fe. 


Fe,  Ni,  Co,  Mn,  Cr,  Cu,  etc. 
Fe,  Ni,  Co. 


Experiment  IV.— Prepare  a  clear  colourless  bead  of  borax  in  a  ring  or 
loop  of  platinum  wire  about  3  or  4  m.m.  (or  %  inch)  in  diameter,  then  take 
up  a  small  quantity  of  the  powdered  substance  by  dipping  the  hot  bead  into 
it  and  re-fuse. 

1.  Heat  in  the  outer  or  oxidizing  blowpipe  flame. 

2.  Heat  in  the  inner  or  reducing  blowpipe  flame. 

Or  the  bead  may  be  fused  in  the  corresponding  areas  of  the  bunsen  flame, 


f  but  the  results  are  not  always  satisfactory. 


Colour  of  Bead. 


Amethyst. 

Blue. 

Brown. 

Green. 

Pink. 

Red. 

White. 

Yellow  to  brown, 
Colourless. 


/;/-  the  Oxidizing  Flame. 


Mil,  Di  (Co  mixed  with  Ni) 

Co,  hot  and  cold  ;  Cu  cold. 

Ni  hot  and  cold. 

Cr,  Cu  (hot),  V  (cold),  U. 

Di. 

Ce,  Fe  ;  Ni  (brown  cold). 

Ag,  Zn. 

Fe  ;  U,  Pb,  Bi,  Sb,  V,   Mo 
(hot). 

Ag,  Al,  Ba,  Ca,  Cd,  Nb, 
Pb,Sb,  SiO,,Sn  (turbid), 
Sr,  Ta,  Te,  Ti,  W,  Zn. 


In  the  Reducing  Flame. 


Ti,  cold. 

Co,  hot  and  cold;   Nb. 

Mo. 

Fe,  U,  Cr,  V. 

Di. 

Cu  (opaque  when  in  excess) 

Ag,   Bi,   Cd,  Nb,   Ni,   Pb, 

Sb,  Te,  Zn. 
Ti,  W,  V,  Mo  (hot). 

Al,  Ba,  Ca,  Ce,  Cu,  Di,  lyi, 
Mn,  SiO,,  Sn,  (turbid), 
Sr,  Ta. 


Confirm  for  Mn  and  Cr  by  fusing  on  Pt  foil  with  Na.2CO3  and  KNO3,  a 
blue  residue  :  Mn  ;   a  yellow  residue  :  Cr. 

*Magnetise  the   blade   of   a    pen-knife   by   drawing  a   magnet   over  it  4  or  5  times  in  the  same 
direction. 


TABLES    FOR    Q 


IVK   CHEMICAL   ANALYSIS 


Experiment  F— Flame  tesE^Take  up  a  little  of  the  substance  on  a 
very  thin  platinum  wire  moistened  with  cone.  HC1  and  heat  it  at  the  base  of 
the  bunsen  flame. 


Results.                   0      l 

*  *^   f    m 

Inferences. 

The  flame  is  coloured  bright  yellow. 

Na. 

,,         ,,         ,,         yellowish-red, 
n         M         t>         red.                             .   * 

£   •    . 

,,          ,,          ,,         crimson. 
,,         ,,          ,,         pale  green, 
green.        ^^ 

ft.                                             ^  ;  , 

Ba  and  phosphates^^^L 
Cu,  B,03- 

deep  greer^^ 

Tl. 

,,          ,,          ,,         vivid  blue. 

Cu.         • 

bluish-grey.                 g^ 

As,  Sb,  Pb. 

,,          ,,          ,,         lavender. 

K, 

Confirm  for  borates  ;    heat  the  substance  , 

moistened    with  a  little   H^SCX    on  a 

clean  platinum  wire  :  green  colour. 

Confirm   for  K  ;    view  the  flame  through 

blue  glass  :  lilac  to  red  colour. 

II 


,  ^Experiment  VI  —  Heat  the  substance  on  charcoal  in  the  inner  flame. 


Results. 


Inferences. 


t 


A    white    incrustation    is    formed   on    the 
charcoal. 

A  white  incrustation  far  from  the  test  and 
an  odour  of  garlic  is  emitted. 

A    white   incrustation    with    slight    acid 
odour. 

A    yellow    incrustation    when  hot,    white 
when  cold. 

Confirm    for   Zn ;     moisten    with  Co2NO3 
and  heat  again  :  green  colour. 

A     reddish-brown     incrustation     readily 
volatilized. 

A    dark    red    incrustation ;     an    offensive 
odour  as  of  decaying  horse-radish. 


HgCl,. 

As. 

Te. 

Zn. 

Zn. 

Cd. 

Se. 


88 


TABLES    FOR    QUAI^ITAT 


CAL   ANALYSIS 


fusion  mixture)  and  KCy  and  heat 


Experiment   VII  —  Mix  with  NaK( 
on  charcoal  in  the  reducing-  flame. 

Alternative  method. — Flatted  out  a  small  piece  of  Na,   wrap  the  sub- 
stance in  it,   and  heat  on  charcoal  before  the  blowpipe. 

^J^rape  out,  with  a  magndfcsed  penknife  blade,  into  a  small  mortar,  grind 
with  water;  wash  away  the  cjj^rcoal  powder  and  examine  for  metallic 
particles. 


cliai 


Results. 


Inferences. 


-4 


ueed  to  the  metallic  state. 

'«)—  With  incrustation 

White  malleable  beads  :  slight  yellow  in- 
crustati^Ph,  white  when  cold. 

Bluish-white  malleable  beads  which  mark 
paper  ;  pale  yellow  incrustation  when 
cold. 

White  brittle  beads  with  acicular  crystals 
of  Sb.2O;5.  Copious  white  fumes  and 
incrustation. 

Pale  reddish  brittle  beads,  dark  orange 
incrustation  when  hot,  yellow  when 
cold. 

(b)~Without  Incrustation 

White  malleable  metallic  beads. 

Confirm  for  Ag  ;  dissolve  in  HNO3,  add  a 
dtop  of  HC1  :  white  ppt.  of  AgCl, 
which  darkens  on  exposure  to  light. 

Grey  metallic  particles  ;  non-magnetic. 
"  Yellow  metallic  beads. 
Malleable  particles  or  beads  of  red  metal 

Black  metallic  infusible  powders  ;  mag- 
netic. 

Test  for  S  by  scraping  out  some  of  the 
fused  mass  and  placing  it  on  a  silver 
coin  with  a  drop  of  water  :  a  black 
stain  of  AgS  left. 


Sn. 
Pb. 

Sb. 
Bi. 

Ag. 


Pt. 

Au. 

Cu. 

Fe,  Ni  and  Co. 

S   from    sulphates    or    sul- 
phites. 


Experiment  VIII— Match  test— Hold  a  piece  of  crystallized  Na2C03ioH20 
in  the  flame  until  it  begins  to  fuse  superficially,  rub  the  untipped  end  of  a 
wooden  match  in  this  until  the  wood  is  saturated  with  Na^CO*,  char  this  end 
of  the  match  and  then  dip  it  into  the  finely-powdered  substance  and  heat  it 
again  in  the  upper  reducing  area  of  the  bunsen  flame.  Grind  the  product 
with  water  in  a  mortar  and  search  for  metallic  particles. 


TABLES   FOR 
Results. 
Malleable  metallic 


CHEMICAL   ANALYSIS 


89 


Inference. 


bluish- white. 

yellow. 

red. 
Brittle  metallic  particles — white. 

A.     pink  tinge. 
Magnetic  particles.  4 

Confirm  in  each  case  by  dissolving  in  acids 
and  applying  special  testj 


Ag,  Sn. 

Pb. 

Au. 

Cu. 

Sb. 

Bi. 

re,  Co,  Ni. 


Experiment  IX— Film  test.— Heat  the  substance  on  a  few  fibres  of 
asbestos,  in  the  upper  part  of  the  bunsen  flame  so  placed  under  a  porce- 
lain basin  of  cold  water  (supported  on  a  retort  stand)  that  any  volatile 
matter  may  be  condensed  upon  the  cold  porcelain. 


In  upper  reducing  flame. 

Upper  oxidizing  flame. 

Inference. 

^ 

1.—  Metallic  Film 

2.*^  *&e  Film 

~m 

Grey  Film 

Vv 

Hg-     •               / 

Metallic  lustre 

White 

As                       \ 

Black  film 

Yellow 

Cd.        *  •  C 

»         » 

Brown 

,,         ,, 

White 

Zn. 

,,         ,, 

i 

Sn. 

Velvety  black 

,, 

Sb. 

Black 

Pale  yellow 

Bi. 

,, 

White 

Te. 

Cherry-red 

» 

Se. 

Experiment  X-Expose  the  above  films  to  the  vapour  of  iodine  by 
volatilizing-  some  iodine  from  a  few  threads  of  asbestos,  and  afterwards  to 
SH2  or  (NH4)2S.  The  film  is  coloured. 


TABLES   FOR    QUALITAT 
Upper 


At,  ANALYSIS 


In  upper  reducing  flame. 


' 


3.— Iodide  Film 

Red  or  yellow 

Yellow 


N 


Brown 


Iphide  Film 


Black      BtA 
Yellow 

Brown  to  black 
Pale  yellow 
White 

'Brown  or  yello 
Orange 
Yellow 
Brown 
Brow 


Inference. 


Hg. 

As. 

Pb. 

Cd. 

Zn. 

Sti. 

Sb. 

Se. 

Bi. 

Te. 


Experiment  XI—  Boil  some  of  the  powder  in  a  test  tube  with  NaOH. 


Results. 


Inference. 


Smell  of  NH3  and  white  fumes  of  NH4C1 
when  a  rod  moistened  with  HG1  is 
lowered  into  the  tube. 


Presence  of  NH4  salts. 


o 


.        J)  PREPARATION    OF    THE    SOLUTION. 

Water.— Boil  about  '5  gm.  of  the  finely-powdered  substance  with  dis- 
tilled water,  and  decant  the  clear  solution  from  any  insoluble  residue  ;  repeat 
the  process  as  long  as  anything  is'  dissolved,  ascertained  by  evaporating  a 
drop  of  the  solution  in  a  watch-glass  or  on  platinum  foil.  See  Table  of 
Solubilities. 

Acids.— The  residue  insoluble  in  water  is  first  treated  with  boiling  dilute 
HC1.  If  insoluble  in  dil.  HC1,  try  strong  HC1,  and  if  insoluble  in  this  use 
HNO3  upon  a  fresh  portion  of  the  substance.  Notice  whether  CO2,  SO2, 
HCy,  or  Cl  are  given  off,  also  whether  S,  I,  SiO2,  benzoic  acid,  etc.,  are 
precipitated.  If  insoluble  in  HNO3  alone,  add  3  vols.  of  strong  HC1. 

When  aqua  regia  is  used,  employ  it  in  successive  small  quantities ;  the 
iodide,  bromide,  cyanide,  ferrocyanide,  and  ferricyanide  of  silver  are  decom- 
posed by  boiling  wdth  aqua  regia. 


TABLES   FOR    QUALITATIVE    CHEMICAL  ANALYSIS  9J 

The  aqueous  and  acid  solutions  may  be  mixed  and  examined  together  ; 
but  they  must  be  examined  separately  when  it  is  wished  to  learn  how  the 
acids  and  bases  are  combined  in  a  complex  mixture. 

^** 

Insolub/e.—The   residue   insoluble   in  acids  must  be  carefully 

with   distilled   water   to  remove   acids,  ^ried   and  tested  by  the  Table  for 
Insoluble  Substances. 

A  residuum  or  precipitate  may*  be  due  to  the  preJftce  of  sulphur  or 
sulphides,  iodine  from  iodides  in  the  presence  of-  oxidizing  substan 


iodates  in  the  presence  of  reducing  agents  ;  AgCl,   Hg2Cl2, 

may  have  originally  existed  in  the  mixture  or  may  have  been  formed  by  the 

action  of  acids  ;  silicic,  tungstic,  titanic,  and  molybdic  acids  may  have  been 


r 


set  free  from  their  compounds.  Impossible,  discriminate^between  insoluble 
substances  originally  present  and  those  whichare  precipitated  on  continued 
boiling  with  strong  acids.  See  special  Table  for  Insoluble  Substances. 


Insoluble  cyanides— The  presence  of  insoluble  double  cyanides  may  be 
suspected  when  HCy,  although  not  found  in  the  preliminary  examination, 
is  found  on  treating  the  substance  with  H2SO4.  Examine  by  the  Table  for 
Insoluble  Cyanides. 


METALS    AND    ALLOYS. 

If  the  substance  be  a  metal  or  an  alloy,  first  reduce  it  to  filings  or  thin 
sheets  ;    if  very   brittle    it  can    be  roughly  powdered   on   an  ativil  with 
hammer ;  to  prevent  the  loss  of  fragments,   wrap  the  substance  in  stron 
brown  paper. 

If  it  is  not  quickly  dissolved  by  boiling  HC1,  it  can  be  at  once  treated  * 
with  HNO3of  sp.  gr.  i '2(1:1  aq.),  and  if  this  act  but  slowly  some  strong  HNO3 
of  sp.  gr.  i  '4  can  be  added ;  if  there  still  be  a  residue,  filter  and  wash. 

Solution. — May  contain  traces  of  Au  and  Sb,  also  As  as  oxide  ;  other 
metals  will  be  present  as  nitrates,  and  their  examination  can  be  proceeded 
with  in  the  usual  way,  after  evaporating  off  most  of  the  HNO3. 

Residue.— May  contain  metallic  Au  and  Pt,  test  for  these  separately ; 
Sb  and  Sn  as  oxides  or  arsenates,  Pb2N03,  which  is  insol.  in  strong  HNO3, 
and  Bi  as  arsenate  or  phosphate.  If  this  residue  be  white  then  probably 
only  Sn  and  Sb  as  oxides  are  present.  Strong  HC1  converts  metastannic 
acid  into  metastannic  chloride  which  is  soluble  in  water,  but  insol.  in  cone. 
HC1. 


92  TABLES   FOR   QUAIjTATlV^CHtfytlCAL  ANALYSIS 

Boil  the  residue  with  a  strong  sol.  of  Tartaric  acid,  and  filter. 


Residue — SnO2. 

-.Reduce  <pn  charcoal,  with 
NaaCOs  and  KOJT  :  a1 
white  metal. 

Presence  of  Tin. 


Solution. — Pass  SH2,  an  orange^red  pre- 
:  Sb2Ss. 


Presence  of  Antimony. 


o  separate  the  other  metals,  treat  with  yellow  (NH4).2S  and  filter. 


Residue— Bi2S3. 


Solution — May   contain  As,   Sb,   and  Sn 

IPthio-salts,  which  can  be  detected 
in  the  ordinary  way,  see  Group  Table 
No.  II.  The  P2O5  can  be  tested  for 
in  the  solution  after  the  removal  of 
the  S,  Sn,  Sb,  and  As,  by  warming 
with  (NH4)2MoO4. 


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THE   EXAMINATION  FOR   ACIDS. 
(Acid  Radicles  or  Anions.) 


After  the  bases  have  been  detected,  refer  to  the  Table  of  Solubilities  (see 
index)  to  ascertain  what  acids  form  insoluble  compounds  with  the  bases 
present — all  such  acids  must  necessarily  be  excluded  if  the  substance  is  a 
soluble  one. 

The  acids,  unlike  the  bases,  cannot  all  be  detected  and  separated  in 
systematic  order ;  the  presence  of  each  acid  must  be  confirmed  by  its  most 
characteristic  special  tests.  Several  of  the  acids  should  have  been  detected 
during  the  preliminary  examination  when  testing  for  the  bases,  e.g.,  CO2, 
SH2,  H2SO3,  HC1O,  HC2H3O2,  H3AsO3  and  many  others. 

The  presence  of  such  organic  acids  as  tartaric,  citric,  benzoic  and 
succinic,  should  also  have  been  more  or  less  definitely  ascertained. 

PRELIMINARY    TESTS    FOR    ACIDS. 

1.  Warm  the  powder  in  a  test-tube  with  dilute  HC1. 


Results. 


Inference. 


Gases  are  given  off— 

A  colourless  gas  with  but  faint  smell  is 
evolved,  which  renders  lime-water 
turbid.  Use  a  glass  rod  for  the 
Ca(OH)2. 

Ditto,  having  the  suffocating  odour  of 
burning  sulphur.  Turns  K2Cr2O7 
sol.  green. 

Ditto,  with  separation  of  sulphur. 

Ditto,  with  odour  of  stale  eggs,  and 
blackens  lead  acetate  paper. 


Ditto,  with  the  odour  of  bitter  almonds. 
Reddish-brown  fumes. 

A  yellow-green  gas,  of  suffocating  odour, 
which  bleaches  indigo  and  other 
vegetable  colours. 


CO2,  from  carbonates,  and 
from  cyanides  and  cyan- 
ates  containing  carbonates 

SO2,  from  sulphites. 


SO2,  from  thiosulphates. 

H2S,  from  sulphides,  except 
Au2S3,  PtS2,  AgaS,  HgS, 
CuS,  Bi2S3,  and  As2S3 ; 
these  however  give  off 
H2S  in  presence  of  zinc 
and  HCL* 

HCN  from  cyanides. 

NO  and  NO2  from  nitrites. 

Cl,  from  hypochlorites. 


*  S  in  insol.  sulphides  and  sulphates  is  best  detected  by  the  match  and  silver  coin  tests. 

101 


102 


EXAMINATION    FOR    ACIDS 


2.  Warm  a  portion  of  the  substance  with  H2S04  (i  add  to  i  water). 


Results. 


Gases  are  given  off— 


Smell  of  vinegar. 

Add   i  c.c.  alcohol  :  ethyl  acetate  odour. 

Strong  acid  fumes. 


Inference. 


CO2,  H2S,  SO2,  NO,  and 
HCN,  have  already  been 
detected  by  means  of  dil. 
HC1. 

Acetates. 
Ditto. 

HC1,  HF  (HCN  from  ferro- 
and  ferricyanides)  H2S2O3, 
HC1O,  HCNO. 


3.  Warm  with  a  few  drops  of  cone.  H2S04  (the  heat  must  not  be  sufficient 
to  drive  off  the  H2S04). 


Colourless  gas  evolved — 

With  irritating  odour,  gives  white  fumes 
with  NH3.  Add  MnO2  :  Cl. 

Corrodes  glass. 

CO  evolved  without  blackening. 

CO  and  CO2  evolved.  Absorb  CO2  by 
Ca(OH)2  and  burn  the  CO. 

Peculiar  odour,  mixture  of  H2S,  SO2  and 
HCN  with  precipitation  of  S ;  fumes 
redden  paper  moistened  with  FeCl3. 

CO,  CO2,  SO2  and  odour  of  burnt  sugar ; 
the  substance  also  blackens,  tartaric 
acid  chars  rapidly,  citric  but  slowly. 

The  gas  re-ignites  a  glowing  splinter. 


Coloured  gases  are  evolved— 

Violet  vapours  which  turn   starch   paper 
blue. 

Reddish-brown  vapours  which  turn  starch 
paper  yellow. 

Greenish-yellow   gas   with    small    explo- 
sions. 

Brownish-yellow  irritating  vapours. 

Confirm  for  HNO3  by  adding  fragments  of 
Cu  :  red  fumes. 


HC1. 

HF. 

Formic  acid. 
Oxalic  acid. 

Thiocyanates. 

Tartaric  and  citric  acid. 


Oxygen  from  chromates, 
permanganic  acid,  per- 
oxides, and  other  easily 
decomposed  compounds 
rich  in  oxygen. 

Iodides  (and  iodates  in  pre- 
sence of  reducing  agents). 

Bromides  and  bromates. 

Chlorates. 

Nitrates. 


EXAMINATION   FOR    ACIDS 


103 


N.B. — In    treating    with    acids,    amongst    the  substances    which   may 
separate  out  are  the  following  : — 


Results. 


Inference. 


White  sulphur  (with  H2S). 
Yellow       ,,       (withSOa). 

Iodine 


Colourless  gelatinous  silica. 

Confirm  for  SiO2  by  microcosmic  salt  bead. 
Yellow  (when  hot)  tungstic  acid. 

White  molybdic  acid,  soluble  in  an  excess 
of  acid. 

White  TiO-2. 

Confirm  by  adding  a  fragment  of  Zn  and 
diluting — 

Violet  colour  : 

Blue  turning  to  brown  : 

Blue-green  turning  to  brown  : 

Boracic,  benzoic,  succinic,  uric,  and  other 
acids  separate  out  from  concentrated 
solutions. 


From  polysulphides. 

From  thiosulphates,  poly- 
thionates. 

From  iodides  in  presence  of 
oxidizing,  and  from  io- 
dates  in  presence  of  re- 
ducing bodies. 

From  silicates. 


Tungstates. 
Molybdates. 

Titanates. 


Titanic  acid. 
Tungstic  acid. 
Molybdic  acid. 


PREPARATION   OF   THE   SOLUTION. 

As  many  of  the  bases  interfere  with  the  reactions  of  the  acids,  it  is 
necessary  to  remove  them  before  proceeding  to  test  for  the  latter. 

Therefore  boil  a  portion  of  the  original  substance  with  pure  Na2CO«  (free 
from  SO4  and  Cl)  which  precipitates  nearly  all  the  metals,  except  the  alkalis, 
as  carbonates  ;  filter  and  add  to  the  filtrate  a  few  drops  more  Na2CO3,  if  no 
further  precipitate  is  thrown  down  boil  the  solution,  now  containing  all  the 
acids  as  salts  of  sodium. 

But  if  H3As03,  H3As04,  H2MoO4,  H2WO4,  H2SeO4,  H2TeO4  or  H2CrO4 
have  been  found  amongst  the  bases,  first  pass  the  SH2  through  the  slightly 
acid  solution  and  filter  ;  warm  the  filtrate  to  drive  off  excess  of  SH2  and 
neutralize  with  NH4OH,  and  then  remove  any  bases  of  Groups  III,  IV  and 
V  by  NaaCO8.  as  before. 


104 


EXAMINATION    FOR   ACIDS 


Divide  the  solution  into  4  parts. 

(a)    Acidify  one  portion  with  dilute  HC1. 

(d)    Acidify  another  portion  with  dilute  HN03. 

(c)  Acidify  the  third  portion  with  dilute  HC2H302. 

(d)  Neutralize  the  fourth  portion  with  dilute  HC2H302. 


(«).    HC1  Solution. 
Add  BaCl2  sol. 

a.  A  white  ppt.  insol.  in  boiling  HC1 

b.  Filter,  if  necessary,  and  add  Br  aq.,  a  white  ppt. 

c.  A  white   gelatinous  ppt.  which  evolves  SiF4,    on 

warming  with  H2SO4 

Add  FeCl3  sol. 

a.  A  blood-red  colour,  destroyed  by  HgCl2 

b.  A  dark-blue  ppt.     (Prussian  blue.) 

c.  A  brown  or  green  solution 

Confirm  for  H3FeCy6  by  FeSO4  :  deep  blue  ppt.  If 
both  H4FeCy6  and  H3FeCy6  are  present,  filter  off 
the  ppt.  reduced  by  FeCl3  and  add  H2SO3  to  the 
filtrate,  a  blue  ppt. 


:  H2S04: 

:  H2SO3  or 

HaS2O8. 

:  H2SiF6. 


HCyS. 

H4FeCy6. 

H3FeCy6. 


H3FeCy(, 


(b).    HN03  Solution. 

Adfl  AgN03  sol. 

A  white   or  yellowish   ppt.    sol.  in   NH4OH  :  AgCl, 
AgBr,  AgCy,  AgBrO3  or  AgIO3. 

a.  AgCl  (white).     Confirm   by  MnO2  and  H2SO4,  Cl 

evolved,  which  bleaches  litmus  paper. 

b.  AgBr  (yellowish).       Confirm  by  MnO2  and  H2SO4 

:  red  fumes,  or  by  Cl  and  CSa  :  red-brown  colour. 

c.  AgCy  (white).      Confirm  by  igniting  on  porcelain, 

metallic  silver  is  left. 

d.  AgBrO3  (white),  crystalline. 

e.  AgIO3,  white ;  H2SO3  converts  it  into  yellowish 

Agl 


:  HC1. 
:  HBr. 

:  HCy. 
:  HBrO3. 

:  HI08. 


(c).    Acetic  Acid  Solution. 

1.    Add  CaCl2  sol. 

A  white  ppt.       This    may    be   due    to  HF,  H2C204  or  H4FeCy6. 


EXAMINATION    FOR    ACIDS 


105 


2.  Add  AgNO«  sol. 

A  pale  yellow  or  white  ppt.  insol.  in  NH4OH. 

a.  Agl.       Warm     with    MnO2    and    H2SO4,    violet 

vapours.     Add  Cl  aq.  and  CS2  :  purple  sol. 

b.  A  white  ppt.  of  AgCyS 

c.  A  reddish-brown  ppt. 

d.  A   black    ppt.      Test   the   original  sol.    with  Na 

nitroprusside  :  a  violet  colour 


HI. 
HCyS. 
H3FeCy6. 
SH2  or  a  soluble 
sulphide. 


W    Neutral  Solution. 
1.    Add  AgNOs  sol. 

I.  A  white  ppt.  sol.  in  NH4OH. 

a.  From  strong  sols. 

b.  The  original  sol.  does  not  coagulate  albumen 

c.  The  original  sol.  coagulates  albumen 

d.  The  ppt.  becomes  grey  on  boiling 

e.  The  ppt.  blackens  on  boiling 

f.  On  warming  becomes  grey 

Malic  acid   yields    a   white   ppt.    with    Pb2C2H3O2, 
which  melts  on  boiling  the  liquid. 

g.  On  warming  :  metallic  mirror 

h.  The  sol.  in  NH4OH  on  warming  yields  a  mirror. 
The  original  sol.  (neutral)  :  a  ppt.  with  CaCl2 

Tartarie  and  Citric  Aeids. — Precipitate  the  tartaric 
acid  by  a  strong  sol.  of  K  acetate  in  alcohol,  add 
acetic  acid,  stir  well  and  allow  to  stand.  Filter 
off  the  KHC4H4O6— boil  off  the  alcohol  and  add 
BaHoO2  or  Ba  acetate  :  a  white  ppt. 

Other  acids  also  give  white  ppts.,  e.g.,  thiocyanic, 
hydroferrocyanic.  See  (b)  HNO8  solution. 

II.  A  coloured  ppt.  sol.  in  NH4OH. 

a.  Yellow.      Confirm  for  P2O5  by  (NH4)2MoO4 

b.  Pale  yellow 

c.  Brown 

d.  Red 

e.  Orange 


H8B08. 

H4P207. 

HP03. 

H2SO3. 

H2S203. 

Oxalic 


and 


malic  acids. 

HCHO2. 

Tartaric  acid. 

Citric  acid. 


H3P04. 

H3As03. 

H3AsO4. 

H2Cr04. 

H4Si04. 


106  EXAMINATION    FOR    ACIDS 

2.    Add  FeCl3  sol. 

a.  A  red  colour,  destroyed  by  boiling  and  a  brown 

basic  salt  precipitated 

b.  A  violet-red  colour  destroyed  by  boiling 

c.  A  pale  yellow  ppt.  of  basic  ferric  benzoate 

d.  A  reddish  brown  ppt.  of  basic  ferric  succinate 


:  HCHO2     and 
HC2H302. 

:  H2S203. 

:  Benzoic  acid. 

:  Succinic  acid. 


To  distinguish  between  benzoie  and  sueeinie  acids.— Boil  the  mixed  pre- 
cipitate with  NH4OH,  filter,  add  alcohol  and  BaCl2,  white  Ba  succinate  is 
thrown  down.  Benzoic  acid  does  not  give  a  precipitate. 

To  detect  HCN  in  the  presence  of  HC1,  wash  the  Ag  precipitate 
obtained  in  the  HNO3  sol.  (b)  and  ignite  on  a  piece  of  porcelain.  Dissolve  the 
metallic  Ag  left  by  the  AgCN  in  nitric  acid,  and  test  for  Ag  in  the  solution 
with  HC1  as  usual. 

To  detect  HBr  in  the  presence  of  HC1. — Distil  the  dried  chloride  and  bro- 
mide with  K2Cr2O7  and  H2SO4.  Remove  the  Br  from  the  chromyl  chloride  in 
the  distillate  by  means  of  ether. 

To  detect  HC1  in  the  presence  of  HI. — Digest  the  mixed  Agl  and 
AgCl  ppts.  with  NH4OH,  filter  ;  the  Agl  is  insoluble.  Dilute  HNO3  reprecipi- 
tates  the  AgCl  from  the  filtrate. 

The  pale  yellows  of  Agl  and  AgBr  are  not  always  visible  when  mixed 
with  white  precipitates,  hence  very  little  importance  can  be  attached  to  the 
colour  of  the  precipitate  obtained  on  adding  AgNO8. 

To  distinguish  between  HC1,  HBr,  and  HI. — Precipitate  the  HI  as  Cu2I2 
by  means  of  CuSO4  and  H2SO3 ;  filter,  remove  the  CuSO4  by  pure  NaOH, 
evaporate  the  filtrate  to  dry  ness,  and  test  for  Cl  by  K2Cr.2O7  and  H2SO4,  and 
for  Br  by  Cl  water  and  ether,  CHC13  or  CS2.  Or  dissolve  out  the  AgCl  by 
boiling  with  (NH4)2CO3 ;  add  a  little  Cl  water  and  starch  paste  to  the  residue, 
a  blue  colour  :  iodine.  To  another  part  add  an  excess  of  Cl  water  to  oxidize 
the  iodine,  shake  with  CS2,  a  brown  colour  :  bromine. 

To  distinguish  between  chloride  and  chlorate. — Precipitate  the  chloride 
by  AgNO3,  filter  off  the  AgCl.  Reduce  the  chlorate  to  chloride  by  zinc  and 
H2S04,  then  add  AgNO8  :  AgCl. 

To  distinguish  between  HC1,  HBr,  HI  and  HCN.— Test  for  HCN  by  treat- 
ing the  mixture  in  a  dish  with  dilute  H2SO4,  covered  with  an  inverted  porcelain 
dish  containing  a  drop  of  (NH4)2S  or  AgNO3,  to  absorb  the  HCN  ;  the 
NH4CNS  formed  will  give  the  blood-red  colouration  with  FeCl3,  and  the 
AgNO3  a  white  precipitate  of  AgCN. 


EXAMINATION    FOR    BASES 


A  white  or  slightly  yellow  precipitate  may  contain  silver  salts  of  HC1, 
HBr,  HI,  HCN,  H4FeCy6,  HIO3,  HBrO3 ;  and  if  orange,  HsFeCy6  in 
addition. 

To  distinguish  between  hypoehlorites  and  chlorates. — Add  NaOH  and 
then  MnSO4  :  brown  ppt.  of  MnO2.H.2O,  due  to  the  oxidation  by  the  hypo- 
chlorite.  Filter,  and  decompose  the  NaCl  thus  formed  in  the  solution  from 
the  hypochlorite  by  AgNO3  sol.  Filter  off  the  AgCl  and  add  Zn  and  H.2SO4 
to  the  filtrate  (to  reduce  the  chlorate  to  a  chloride),  filter  and  add  AgNO3,  a 
white  ppt.  of  AgCl  indicates  the  former  presence  of  a  chlorate. 

To  distinguish  alkaline  cyanides,  ferroeyanides,  ferrieyanides  and  thio- 
eyanates. — Saturate  with  CO.2  and  distil  off  the  HCy  ;  add  excess  of  FeCls  to 
the  residue  in  the  flask,  a  precipitate  of  Prussian  blue  :  ferroeyanide.  Filter, 
a  red  filtrate  shows  the  presence  of  thioeyanates ;  add  FeSO4  :  a  precipitate 
of  Turnbull's  blue  :  ferrieyanide. 

Cyanide,  chloride,  bromide,  iodide,  ferroeyanide,  ferrieyanide,  and 
thiocyanate.— Precipitate  with  AgNO3,  filter  and  ignite  ppt.  (all  except  the 
haloid  compounds  are  decomposed).  Fuse  the  ignited  ppt.  with  Na2CO3, 
digest  with  boiling  water  and  test  the  solution  for  Cl,  Br,  and  I  in  the  usual 
way. 

To  detect  a  soluble  sulphide,  thiosulphate,   sulphite   and  sulphate  in  a 

mixture.      Add  CdCO3  and  agitate,  extract  with  dil.  acetic  acid  and  filter. 


A  residue  of  CdS  (yellow) 
indicates  the  presence  of  a 
soluble  sulphide. 


Filtrate.     Add  BaCl2  to  the  cold  solution. 


Precipitate  :  BaSO4  and 
BaSO3,  warm  with  dil. 
HC1  and  filter. 


Residue. 

BaSO4  :  sul- 
phate. 


Filtrate. 
Add  Cl  wa- 
ter, a  white 
ppt :  sulphite 


Filtrate  contains 
thiosulphates.  Add 
HC1  and  warm,  a 
white  ppt.  :  thiosul- 
phate. 


To  detect  a  soluble  sulphide  in  the  presence  of  free  SH2,  add  a  drop  or  two 
of  Na  nitroprusside  :  a  purple  colour. 


INSOLUBLE   SUBSTANCES. 


The  residue  left  after  treatment  with  HC1  and  HNO3  may  contain  the 
following: — Carbon  and  chrome-iron  (black),  sulphur,  Agl  and  PbCrO4, 
(yellow);  certain  double  cyanides,  SiO2  and  most  silicates,  AgCl,  AgBr,  PbCl2, 
PbSO4,  SnO2,  Sb2O4,  BaSO4,  SrSO4,  CaSO4,  CaF2  and  other  fluorides,  certain 
arsenates  and  metaphosphates  (white).  Ignited  A12O3  (white),  Cr2O3  (green), 
and  Fe>O3  (brown).  A  few  of  the  above  are  slightly  soluble  in  acids  and 
should  have  been  already  found  in  the  solution,  e.g.,  PbCl2,  PbSO4, 
PbCrO4,  Fe2O3,CaSO4,  fluorides,  arsenates  and  some  others. 


PRELIMINARY   TESTS. 

a.  The  insol.  residue  is  white. 

1.  Moisten  with  (NH4)2S  solution,  it  blackens  :  Ag-,  Pb  salts. 

2.  Heat  in  an  ignition  tube,  it  fuses  :  Ag-  and  Pb  salts.     It  is  infusible 
and  remains  white  :  Si02,  (PbS04),  A1208,  BaS04,  SrS04,  CaS04,  CaF2. 

3.  Exposed  to  sunlight  it  becomes  slate-coloured  :  AgCl. 

4.  Confirm  for  Pb  and  Ag  by  the  blowpipe  on  charcoal  :  white  malleable 
beads. 

5.  Confirm  for  SiO2  in  the  microcosmic  salt  bead ;  a  skeleton  of  Si02  : 
silicates. 

6.  Confirm  for  Al2O3by  heating  on  platinum  wire  with  Co2NO3  solution  ; 
a  blue  residue  :  A1203. 

7.  Confirm  for  Ba,  Sr,  and  Ca,  by  the  flame  test  with  HC1 ;  apple-green 
colour  :  Ba  ;  crimson  :  Sr  ;  brick-red  :  Ca. 

b.  The  insol.  residue  is  yellow. 

Heat  in  an  ignition  tube ;  it  fuses,  SO2  evolved  and  yellow  drops 
sublime  :  S.  Infusible,  darkens  on  heating  :  Sn02,  Sb204. 

Confirm  for  Sn  and  Sb  on  charcoal  or  by  match  test ;  malleable  beads  : 
Sn  ;  brittle  hard  beads  :  Sb. 

c.  The  residue  is  green. 

Fuse  in  borax  bead  ;  green  colour  :  Cr2O3. 

1 08 


INSOLUBLE  SUBSTANCES  109 

d.  The  residue  is  brown  or  black. 

Infusible,  leaves  magnetic  residue  when  heated  on  charcoal  :  Fe2O3. 
Black  residue  burning  entirely  away.     Confirm  by    igniting  with  KNO3 
on  Pt  foil ;  it  scintillates  :  C. 


TREATMENT  OF  THE   INSOLUBLE  RESIDUE. 

1.  If  C  or  S  has  been   detected,  the  residue  must  be  ignited  in  an  open 
crucible. 

2.  Certain   substances,    if  present,    may   be    dissolved   out    by   special 
reagents,  and  tested  for  separately,  viz.  : — 

AgCl,  AgBr,  Agl,  soluble  in  strong  KCy. 
PbCl2  soluble  in  boiling  water. 
PbSO4  soluble  in  ammonium  acetate. 

3.  The  dry  residue  is  mixed  with  four  times  its  bulk  of  fusion  mixture 
(Na2CO3,K2CO3)  and  fused  in  a  Pt  crucible  (or  on  a  piece  of  Pt  foil  turned  up 
at  the  edges)  over  a  bunsen  burner  until  all  effervescence  ceases. 

4.  If  compounds  of  easily  reducible  metals  (Ag,   Pb,  Sb,  Bi,  etc.)  are 
present,  they  must  first  be  removed  by  suitable  solvents,  because  the  above 
metals  form  easily  fusible  alloys  with  Pt ;  or  the  fusion  may   be  made  in  a 
small  porcelain  crucible,  on  a  crucible  lid,  or  on  a  piece  of  a  broken  porcelain 
dish.     The  silica  of  the  porcelain  is  attacked  by  the  fusion  mixture,  hence  if 
SiO2  has  been  indicated  in  the  preliminary  tests,  fuse  on  Pt  after  removing 
the  Ag,  etc.     A  nickel  crucible  can  be  used  in  most  cases. 

Dissolve  the  fused  mass  in  hot  water.     Filter. 


Residue.    Contains  the  bases. 

(a).  If  Ag  or  Pb  has  been  found 
extract  with  HNO3. 

(£).  If  Ag  and  Pb  are  absent,  ex- 
tract with  HC1. 

Filter  and  wash. 


Filtrate.    Contains  the  acids. 

Neutralize  with  HNO3  and  boil. 
If  SiO2  be  present,  evaporate  to  dry- 
ness,  take  up  with  HNO3  and  filter 
hot. 


Residue. 

Filtrate. 

Residue          Filtrate.      Examine   for 

SnO2,  Sb2O4,  CaF2, 

Ag,   Pb,  Sn,   Sb, 

acids.      HC1,    HBr,     HI, 

and  chrome  iron. 

Al,    Fe,    Cr,    Ba, 

SiO2. 

H2S04,     H2Cr04,     H3P04, 

Confirm   for    each 
by  special  tests. 

Sr,  Ca. 

Examine   by   the 
Tables      in      the 

H3AsO4,  HF,  all  of  which 
should  have  been  found  in 
the  preliminary  tests. 

usual  way. 

no 


INSOLUBLE   SUBSTANCES 


DETECTION    OP    ALKALIS    IN   SILICATES. 

Mix  *5  gram  of  the  finely-powdered  silicate  with  2  grams  of  NH4F  and 
a  little  strong  H<2SO4  to  a  paste  on  platinum  foil ;  heat  at  a  very  low  temper- 
ature as  long  as  fumes  of  SiF4  are  evolved,  then  raise  the  heat  to  drive  off  the 
H2SO4.  Dissolve  the  residue  in  water  and  test  for  alkalis  on  Pt.  wire  in  the 
usual  way. 

A  second  method  is  to  grind  '5  gm.  of  the  already  finely-powdered 
mineral  with  'i  gm.  NH4C1  and  4  gms.  pure  CaCO3 ;  then  heat  to  bright 
redness  on  platinum  foil  for  20  to  30  minutes.  When  cold,  boil  crucible  and 
contents  in  about  50  c.c.  water,  filter  (the  residue  consists  of  CaO,  SiO2, 
etc. ,  and  need  not  be  examined),  to  the  solution  add  (NH4).2CO3  to  precipi- 
tate the  CaCL2,  filter  and  wash,  evaporate  the  filtrate  to  dryness  and  test  for 
the  alkalis  in  the  usual  way. 


TREATMENT  OP  INSOLUBLE  DOUBLE  CYANIDES. 

The  simple  cyanides  are  converted  into  chlorides  by  boiling  with  strong 
HC1,  but  AgCN,  Ag4FeCy6,  and  Ag8FeCy6  require  to  be  boiled  with  aqua 
regia. 

To  detect  an  insoluble  cyanide  boil  some  of  the  residue  insoluble  in  HC1 
(left  by  the  original  substance)  with  NaOH,  filter,  acidulate  the  filtrate  with 
HC1  and  test  it  for  H4FeCy6  and  H3FeCyc ;  if  either  are  present,  proceed  as 
follows  : — 

a.  Boil  one  part  of  the  substance  with  NaOH  ;  filter. 


Residue. — 

Diss.  in  HC1  and  ex- 
amine for  bases  in  the 
usual  way,  except  Na, 
K. 


Solution.— May  contain  H4FeCyc  and  H3FeCy6 ; 
also  such  bases  as  PbO,  ZnO,  and  A1.2O3 
soluble  in  NaOH.  Pass  SH2  to  remove 
PbO  and  ZnO,  filter,  and  test  filtrate  for 
H4FeCy6  and  H8FeCy6  with  FeCl3  and 
FeS04. 


b.  Fuse  another  portion  with  four  times  its  bulk  of  a  mixture  of  one 
part  NH4NO3,  and  three  parts  (NH4)2SO4.  Dissolve  the  melt  in  HC1,  remove 
heavy  metals  in  the  usual  way,  and  test  for  K  and  Na. 

Test  for  acids  in  the  solution  as  in  a. 


APPENDIX. 


TESTS   FOR    CERTAIN    ELEMENTS   IN    CARBON    COMPOUNDS. 

(See  also  Preliminary  Tables,  p.  82  and  p.   101.) 


To  detect  hydrogen,  nitrogen,  sulphur,  &c.,  in  carbon  compounds  : — 

1.  Hydrogen. — Mix  the  substance  with  dry  CuO  and  heat  in  an  ignition 
tube,    water  is  given  off  and  condenses  in  the  cooler   part   of  the   tube  : 
Hydrogen. 

2.  Carbon. — The  gas  given   off  renders  lime-water  turbid  (a   drop   of 
Ca(OH)2  on  the  end  of  a  glass  rod  is  sufficient)  :  CO2  from  Carbon. 

3.  Nitrogen. — Its. presence   may   be    indicated   by  the  odour  of  singed 
feathers  when  the  substance  is  burnt.     Mix  the  powdered  substance  with 
soda-lime  and  heat  in  an  ignition  tube,  the  odour  of  NH3  :  Nitrogen.     NO2 
compounds  do  not  give  off  NH3. 

4.  Sulphur   and  Phosphorus. — i.   Mix  with  pure  Na.2CO3  and  pure  KNO3 
or  with  Na  peroxide  and  fuse  in  an  ignition  tube,  dissolve  out  with  water 
and  test  for  HaSO4  by  BaCl2,  and  H3PO4  by  am.  molybdate.     2.  Ignite  with  a 
very  little  metallic  Na,  and  dissolve  in  aq.    Add  a  drop  of  Na  nitroprusside  to 
the  clear  sol. ,  a  purple  colour  :  Sulphur. 

5.  The  Halogens. —  i.   Heat  a  copper  wire  in  the  bunsen  flame  until  it 
ceases  to  give  a  green  colour  to  the  flame,  then  dip  it  into  the  substance  to 
be  tested,  a  vivid  blue  flame  indicates  the  presence  of  a  halogen.     2.  Mix 
with  pure  CaO,  heat  in  an  ignition  tube,  dissolve  out  with  water,  filter  and 
test  for  HC1,  HBr  and  HI  in  the  usual  way. 

TESTS   FOR   CERTAIN   ORGANIC   LIQUIDS. 

Heat  a  drop  or  two  in  a  dry  test  tube. 


Results. 


It  volatilizes  completely. 

The  vapour  is  non-inflammable,  pleasant 

ethereal  odour 
The  vapour  burns  with  a  pale  blue  flame 


Inference. 


Chloroform. 


Alcohol,  Aldehyde,  Chloral, 


Carbon  bisulphide, 
in 


112 


APPENDIX 


Results. 


Inference. 


The  vapour  burns  with  pale  blue  flame, 
with  slight  charring  and  unpleasant 
odour 

The  vapour  burns  with  luminous  flame 

The  vapour  burns  only  on  warming, 
smoky  luminous  flame 

The  vapour  is  acid,  pungent  and  inflam- 
mable 


Glycerol. 


Ether,    Et.  acetate,      nitro- 
benzene. 

Paraffin     oils,     turpentine, 
benzene,  aniline. 

Formic  or  acetic  acids. 


TABLE   OF   SOLUBILITIES. 


1 .  All  the  salts  of  Li,  NH4,'  Na,  and  K  are  soluble  in  water. 

2.  All  normal  nitrites,  nitrates,  hypochlorites  and  chlorates  are  soluble 
in  water.     If  a  compound  is  soluble  in  water  it  is  usually  soluble  in  dilute 
acids ;  Ag,  Hg',  and  Pb  salts,  however,  yield  insoluble  chlorides  with  HC1, 
and  many  salts  readily  soluble  in  water  are  insoluble  in  concentrated  acids, 
e.g.,  AgNO3  in  HNO3,  BaCl2  in  HC1. 


Name  of  Salt. 


Soluble  in  Water. 


Sol.  in,  or  decom- 
posed by,  HC1  or 
HN03. 


Insol.  in  acids. 


Acetates 


Arsenates  and 
Arsenites 


Benzoates 

Borates 

Bromides 

Carbonates 


All  sol.  except  some 
basic  acetates  (Ag  and 
Hg'  difficultly.) 

Of  alkalis,  and  acid  ar- 
senates  of  Ba,  Sr,  Ca. 


Of  alkalis,  Ba,  Sr,  Ca, 
Mg,  Mn",  Zn,  Fe". 

Of  alkalis.  Many  others 
are  slightly  sol. 

Of  alkalis,  Ba,  Sr,  Ca, 
Mg,  Al,  Zn,  Mn,  Ni, 
Co,  Fe,  Hg",  Cu", 
Cd,  Au,  Pt  (Pb 
slightly). 

Of  alkalis. 


Basic  acetates. 


Nearly  all,  (Sb  ar- 
senate  slightly) 
Ag,  Pb,  Hgx de- 
composed. 

Nearly  all. 
All. 

Bi,  Sb,  Pb,  Cu', 
and  HgBr2  in 
dil.  HC1. 


All    decomposed. 
Native     FeCO3, 
MgCO3,      and 
MgCa(C03)2, 
slowly. 


AgBr,  HgBr. 


APPENDIX 


Name  of  Salt. 

Soluble  in  Water. 

Sol.  in,  or  decom- 
posed by,  HC1  or 
HN03. 

Insol.  in  acids. 

Chlorides 

Of  alkalis    and   of    all 

AgCl,  HgCl. 

metals  except  Ag,  Hg' 

Cu',  Au',  Pt"  ;   PbCl.2 

.L/e  -t-t 

sol.  in  boiling  water. 

Chlorates 

All  sol. 

* 

Chro  mates 

Of  alkalis,  Sr,  Ca,  Mg, 

Nearly  all. 

Ignited  PbCrO4 

Zn,Mn,Fe'",Hg",Cu. 

Native  Cr  iron. 

Citrates 

Of     alkalis,      Mg,     Al 

All. 

(mono),  Cr,  Cu,  (Ba), 

Pb  (di),  Ca  (tri),  (Zn, 

- 

Ni,  Co,  Fe  slightly). 

Cyanides 

Of  alkalis,  Sr,  Ca,  Mg, 

Fe"  in  hot  cone. 

Hg",      Au,     Pt,     (Ba 

HC1.     Single 

slightly). 

cyanides;  AgCN 

in  aqua  regia. 

Ferrocyanides 

Of  alkalis,  (Ba,  Sr,  Ca, 

Cd,  Mn,  in  HC1  ; 

Both  ferro-  and 

Mg,  Bi,  slightly). 

most    others   in 

ferri-  cyanides 

aqua  regia. 

are     d  e  c  o  m- 

Ferricyanides 

Of  alkalis  (Ca,  Mg,  Fe'", 
Pb,  slightly). 

posed  by  boil- 
ing with  KOH 

Fluorides 

Of  alkalis,   Cr,  Ag,  Pt, 

Nearly  all. 

Fluorspar      de- 

Hg". 

BaF2sol.  inHNO3 

composed    by 

H2SO4. 

Fluosilicates 

Of  alkalis,  K   and   Ba 

Of  Ca,  Ba. 

only  slightly,  Al,  Cd, 

Cr,   Ni,   Co,   Fe,  Pb, 

Mg,  Mn,  Sn,  Hg,  Ag, 

Zn. 

Formates 

Nearly  all  sol.,  Sn"  in- 

sol.     Pb  sol.  in  boil- 

ing water. 

Hydroxides 

Of  alkalis,  (Ba,  Sr,  Ca, 

Nearly  all. 

si.  sol.). 

Hypochlorites 

All  sol. 

Ag.    hypochlorite 

decomposed  into 

chlorate  and  in- 

sol. chloride. 

Iodides 

Of  alkalis  (Pb  slightly). 

Hgl     slowly     on 

Ag,    Cu',   Hg', 

boiling. 

Pb,  Pt",  (Hgl 

sol.  in  KI). 

Nitrates 

All    except    the    basic 

Basic  nitrates. 

nitrates. 

Nitrites' 

All  sol.    (Ag  slightly), 

most  basic  nitrites  insol. 

APPENDIX 


Name  of  Salt. 

Soluble  in  Water. 

Sol.  in,  or  decom- 
posed by,  HC1  or 
HN03. 

Insol.  in  Acids. 

Oxalates 

Of  alkalis,  Cr,  Sniv,  Pt, 

All  sol.  in  HC1. 

(Mn  slightly). 

Oxides 

Of  alkalis,  Ba,  Sr,  (Ca, 

SnOo  and  ignited 

Sb.2O,,  SnO,, 

As,  slightly). 

Fe.O3     slightly. 

A1,O3  and 

Ag,  Pb,  Hg  sol. 

Cr2O3     after 

, 

in  HNO3. 

strong  heating 

Pb3O4    d  e  c  o  m- 

posed. 

Phosphates 

Of  alkalis. 

All  sol.  in  HNO3. 

(Ortho) 

Silicates 

Of  alkalis. 

Most  silicates  are 

Many  native  sil- 

d ecomposed 

icates       insol. 

with   separation 

All  are  decom- 

of Si(OH)4. 

posed  by  HF. 

Succinates 

Of    alkalis     and    most 

Ag,  Hg,   Pb,  Cu, 

others,    (Ba,    Sr,    Ca, 

Fe'",  Sn. 

Al,     Zn,     Co,      Fe", 

slightly). 

Sulphates 

Most  sulphates,  except 

Ca  slightly.  Basic 

Ba,  Ca,  Pb,  Sr, 

Ba,  Sr,  Ca,  Pb,  and  a 

sulphates  of  Hg, 

and  anhydrous 

few  basic  ones  (Ag.2SO4 

Fe*YBi,Sn*s61. 

Cr  sulphates. 

si.  sol.) 

in  HC1. 

Sulphides 

Of  alkalis,  Ba,  Sr,  (Ca, 

Most   are  decom- 

Mg, si.). 

posed.     Ag,  As, 

Bi,   Cu,   Pb   are 

sol.    in    HNO3; 

Co,    Hg',    Hg", 

Ni,  req.  aq.  regia 

Sulphites 

Of  alkalis,  (Ba,  Sr,  Ca, 

All  others  decom- 

acid sulphites). 

posed. 

Tartrates 

Of  alkalis  only. 

All  sol.  in  acids. 

Thiocyanates 

Of  alkalis,   Ba,  Sr,  Ca, 

Bi,  Cu,  Hg"  (Hg7 

Fe. 

si.  in  cone,  acid, 

AgCNS  sol.    in 

cone.  HNO3). 

Thiosulphates 

Of  alkalis,  Ca,  Sr,  (Pb, 

All  decomposed. 

Ag,  Ba,  slightly). 

APPENDIX  115 

REAGENTS   FOR   QUALITATIVE  ANALYSIS. 

All  the  solutions  are  equivalent  solutions  except  where  otherwise  stated, 
and  most  of  them  are  prepared  by  dissolving  a  gramme-equivalent  of  the  re- 
agent in  one  litre  of  water. 


Name. 

Formula. 

Equivalent 
or  gms.  per 
litre. 

Preparation  of  Solutions. 

Strength. 

Acetic  acid 

HC2H30-2 

59'58 

Glacial  acetic  acid. 

i77B 

>  5                   5  > 

>  j 

Diss.  294  c.c.  of  glacial 

E 

acetic  acid  in  i  litre  of 

of  aq. 

Citric  acid 

H3C,;H507 

I9O'62 

350  grams. 

5E 

>  j        j> 

>  > 

Diss.  70  gms.  in  i  litre. 

E 

Hydrochloric  acid 

HC1 

36-I8 

Sp.  gr.  ri6i. 

zoE 

»                » 

>  > 

Sp.  gr.  1-084. 

5E 

j  >                >  > 

>  > 

Dilute  200  c.c.  of  5E  to 

E 

i  litre. 

Hydrofluoric  acid 

HF 

19-9 

Sp.  gr.  1-15. 

I2'9E 

Nitric  acid 

HN03 

62-57 

Sp.  gr.  1-5  at  15-5°  C. 

23E 

»          >  > 

>  » 

Sp.  gr.   1-42. 

i6E 

5  >                    » 

>  > 

Sp.  gr.   1-1656.      ,, 

5H 

>  >                     » 

>  > 

Dilute  200  c.c.  of  5E  to 

E 

i  litre. 

J  >                    J  > 

» 

Oxalic  acid 

H2C204 

44-67 

Diss.    94-5     grams,     of 

IE 

HAO4,2H2Oinilitre. 

Sulphuric  acid 

H2S04 

48-67 

Sp.  gr.  i.  8427  at  1  5  -5  °C 

36E 

»  >              >  » 

>  ) 

Sp.  gr.  1-1527. 

5E 

>  >              >  > 

)  > 

Dilute  200  c.c.  of  5Eto 

E 

i  litre. 

Sulphurous  acid 

H2S03 

4073 

Saturated  sol.  in  aq. 

37E 

»              » 

>  > 

Dilute  270  c.c.  to  i  litre. 

E 

Tartaric  acid 

H2C4H406 

74-46 

Diss.  375gms.  in  i  litre. 

5E 

»       75      „ 

E 

Tannic  acid 

CuHioOg 

Diss  10  gms.  in  100  c.c. 

of  aq. 

Bromine 

Br 

79'36 

Br.  sp.  gr.   2.96. 

37E 

Bromine  water 

Br,  aq. 

Saturated  sol.  in  aq. 

iE 

Chlorine       ,  , 

Cl,  aq. 

35'lS 

Saturated  sol.         ,, 

*E 

Hydrogen  peroxide 

H20.2 

16-88 

10  vol.  sol.              ,, 

r8E 

Hydrogen  sulphide 

SH2                 16*91 

Saturated  sol.        ,, 

iE 

u6 


APPENDIX 


Name. 

Formula. 

Equivalent 
or  gms.  per 
litre. 

Preparation  of  Solutions. 

Strength. 

Ammonium  acetate 

<NH4)C2H302 

76'5I 

Neutralize    60    c.c.    of 

E 

glacial  acetic  acid  with 

NH4OH  and  dilute  to 

i  litre. 

,,       carbonate 

(NH4)2C08 

4770 

40  gms.  of  am.  sesqui 

E 

carb.    and    16  c.c.   of 

NH4OH  (-880)  diluted 

to  T  litre. 

,  ,       chloride 

NH4C1 

53'ii 

53   gms.    NH4C1   in    i 

E 

litre  aq. 

,  ,      hydroxide 

NH4OH 

34*8i 

Sp.  gr    -880° 

i97E 

»             j  > 

Dil.    "880    to    sp.    gr. 

5H 

•9643- 

j  >             » 

200  c.c.  of  5K,  diluted 

E 

to  i  litre. 

,  ,       oxalate 

(NH4)2C204 

30-8 

42-6  gms.   (NH4)A04, 

|H 

2H2O  in  i  litre. 

,  ,       sulphate 

(NH4)-2S04 

65-60 

65*6  gms.  in   i  litre  of 

E 

aq. 

,  ,       sulphide 

(NH4)2S 

33*84 

Saturate  600  c.c.  of  E 

5H 

NH4OH  with  SH2  and 

add    400    c.c.    of    E. 

NH4OH. 

Barium  chloride 

BaCl2 

103-38 

122    gms.    BaCl2,2H2O 

E 

in  i  litre  aq. 

Calcium         ,, 

'  CaCl2 

55*o8 

109-5  gms-  CaCla,6HsO 

E 

,,       hydroxide 

Ca(OH)2 

3678 

A  saturated  solution  = 

i  in  600  aq. 

,,       sulphate 

CaS04 

67*57 

Saturated  sol. 

sVE 

Copper  sulphate 

CuS04 

79-22 

i24'75gms.  CuS04,5H.20 

E 

in   i  litre. 

Ferrous  sulphate 

FeS04 

75-42 

139  gms.   FeSO4.7H2O. 

E 

Ferric  chloride 

FeCl3 

53*68 

18.67    gms.    of  Fe   as 

E 

Fe2O3   in    200  c.c.  of 

5E  HC1  and  dil.  to  i 

litre. 

For  neutral  FeCl3  add 

Na2CO3  to  the    FeCl3 

sol.  until  a  ppt.  just 

forms  and  then  filter. 

Gold  chloride 

AuCl8 

100-41 

Dissolve  62  '5  gms.  Au 

E 

in  aqua   regia,    evap- 

orate excess    of    acid 

". 

and  dilute  to  i  litre. 

APPKNDIX 


117 


Name. 

Formula. 

Kquivalent 
or  gms.  per 
litre. 

Preparation  of  Solutions. 

Strength. 

Lead  acetate 

Pb2C2H3O, 

I6r25 

189-5  gms.  Pb2C2H3O2, 

E 

3H20. 

Magnesium      s  u  1  - 

MgS04 

5975 

i23'5gms.  MgSO4,7H3O. 

E 

phate 

Magnesia  mixture 

68    gms.    MgCl2,6H20 

in  500  c.c.    aq.,    add 

165  gms.  NH4C1  and 

300  c.c.  of  ENH4OH 

sol.    and   dilute   to   i 

litre. 

Mercurous  nitrate 

HgNQa 

260*07 

56  gms.  of  HgNO8,H2O 

JK 

dissolved  in    40    c.c. 

5E  HNO3  and  diluted 

to  i  litre  ;  add  a  little 

Hg. 

Mercuric  chloride 

HgCl2 

134-43 

53-7  gms.  HgCl2 

IE 

Platinum         ,, 

PtCl4 

83'5o 

155-86  gms.  H2PtCl6in 

E 

i  litre  aq. 

Potassium   bichro- 

K2Cr2O7 

I46'i4 

146  gms.  in  i  litre  aq. 

E 

mate 

Potassium    c  h  r  o  - 

K2CrO4 

96-47 

96*5  gms.  in  i  litre. 

E 

mate 

Potassium  cyanide 

KCy 

64-70 

65  gms. 

E 

Potassium      ferro- 

K4FeCy6 

91-49 

io5'5gms  K4FeCy6,3H2O 

E 

cyanide 

Potassium      ferri- 

KsFeCyG 

109-4 

109-5  gms. 

E 

cyanide 

Potassium  hydrox- 

KOH 

5574 

280  gms. 

5E 

ide 

> 

Potassium  iodide 

KI 

164*76 

165  gms. 

5E 

Potassium  nitrite 

KNO2 

84'55 

84-5  gms. 

E 

Potassium    thiocy- 

KCyS 

96-53 

97  gms.  in  i  litre. 

E 

anate 

Silver  nitrate 

AgNOa 

168*69 

68'5  gms. 

E 

Sodium  acetate 

NaC2H8O2 

81-46 

540  gms.  NaC2H3O23H2O 

4E 

in  i  litre. 

Sodium  acetate  and 

NaA  +  HA 

250  c.c.  4E  Na  acetate 

E 

acetic  acid 

and  200  c.c.i  7E  acetic 

acid  diluted  to  i  litre. 

Sodium  carbonate 

Na2C03 

52-65 

52  gms.  (anhydrous). 

Sodium  hydroxide 

NaOH 

39-76 

200  gms. 

5E 

Sodium     hypo- 

NaCIO 

73-94 

chlorite 

n8 


APPENDIX 


Name. 

Formula. 

Equivalent 
or  gms.  per 
litre. 

Preparation  of  Solutions. 

Strength. 

Sodium   nitroferri- 
cyanide 

Na2FeNOCy5 

Sodium  phosphate 

Na..HPO4 

47  '05 

119*3  gms-  Na2HPO4, 
I2H2O  in  i  litre. 

E 

Sodium  sulphate 

Na2SO4 

70-55 

i6ogms.  Na2SO4ioH2O 
in  i  litre. 

E 

Sodium     thiosul- 
phate 

Stannous  chloride 

Na2S2O8 
SnCla 

78-53 
94'23 

1  24  gms.  Na2S2O3,5H2O. 

Diss.  ii2'5  gms.  SnCla, 
2H2O  in  200  c.  c.  of  5E 
HC1,  dilute  to  i  litre  ; 
add  a  little  tin. 

E 
E 

Strontium  sulphate 

SrS04 

91-14 

Saturated  solution. 

T**B 

Erdmann's  reagent 
Fehling's  solution 

Froehde's  reagent 

Iodine  in  KI 
Mandolin's  reagent 

Mayer's  reagent 
Nessler's  reagent 

Phenolphthalein 
SehifTs  reagent 
Ammonium  molybdate 

Cuprous  chloride  solution 


SPECIAL     REAGENTS. 

Six  drops  cone.  HNO;5  in  100  c.c.  of  water 
added  to  240  c.c.  of  cone.  H2SO4. 

6 '9  gms.  CuSOi  in  30  c.c.  of  water,  i  drop 
H2SO4,  add  35  gms.  Rochelle  salt  and  10 
gms.  NaOH  in  50  c.c.  water,  make  up  to 
100  c.c. 

Diss.  i  gm.  am.  molybdate  in  100  c.c.  cone. 
H2S04. 

Diss.  i  gm.  I  and  2  gm.  KI  in  50  c.c.  water. 

Warm  '5  gm.  vanadium  chloride  or  oxide 
with  100  c.c.  cone.  H2SO4. 

13-5  gms.  HgCl2  and  50  gms.  KI  in  940  c.c.  of 
water. 

(i)  3-5  gms.  KI  in  10  c.c.  H2O  ;  (2)  r6  gms. 
HgCl2  in  30  c.c.  H2O ;  (3)  3  gms.  KOH  in 
60  c.c.  HsQ.  Pour  (2)  into  (i) slowly,  then 
add  (3). 

i  gm.  phenolphthalein  in  50  c.c.  spirit,  make 
up  to  200  c.c.  with  water. 

To   a   pale   sol.     of    fuchsine    in    water    add 

SO2  until  decolourized. 
Diss.    10  gms.    of  the   salt  in    40  c.c.   of  ^E 

NH4OH,  pour  slowly  into  120  c.c.  cone. 

HNO3,  cool  the  solution ;    decant  for  use 

after  settling  some  hours. 

Digest  CuCl2  with  metallic  Cu  and  HC1. 


APPENDIX 


119 


Indigo  solution 
Litmus  solution 

Litmus  paper 
Turmeric  paper 


Mix  together  i  part  of  indigo  powder  and  4  of 
cone.  H2SO4 ;  allow  to  stand  a  few  days, 
then  pour  into  20  parts  of  water. 

Digest  10  gms.  of  powder  with  250  c.c.  of  warm 
water  for  a  few  hours,  decant  the  clear 
sol.,  add  a  few  drops  HNO3  until  a  dis- 
tinct purple  colour  is  obtained. 

Soak  strips  of  porous  paper  in  the  above 
solution. 

i  part  turmeric  root  (powdered)  digested  in  6 
of  alcohol  and  filtered.  Soak  strips  of 
porous  paper  in  this  solution. 


Borax 

Calcium  carbonate 

Fusion  mixture 

Mieroeosmie  salt 

Soda-lime 


DRY   REAGENTS. 

Na2B4O7,ioH2O.     Fused  :  Na.2B4O7. 

CaCO3.     Use  Iceland  spar. 

10  gms.  Na2CO3  and  13  gms.  K2CO3. 

Na(NH4)HPO4.4H2O. 

Shake  CaO  with  NaOH  sol.  and  dry. 


INTERNATIONAL    ATOMIC    WEIGHTS. 


H  ==  i. 

O  =  16. 

Aluminium 

Al     26-9 

27-1 

Copper 

Antimony 

Sb  119-3 

I20'2 

Erbium     ...     . 

Argon       

A      39'6 

39'9 

Fluorine   ... 

Arsenic     

As    74-4 

75'o 

Gadolinium 

Barium     

Ba  136-4 

i37'4 

Gallium    ...     . 

Bismuth    

Bi    206*9 

208*5          Germanium 

Boron        

B       io'9 

ii 

Glucinum 

Bromine    

Br     79-36 

79-96 

(Beryllium) 

Cadmium  

Cd  in-6 

112*4 

Gold  

Caesium    

Cs  132 

133 

Helium    ... 

Calcium    

Ca    39-8 

40'  i 

Hydrogen 

i 

Carbon      

C       11-91 

12.  OO 

Indium 

Cerium      

Ce  139 

140 

Iodine       ...     . 

Chlorine   

Cl     35'i8 

35'45 

Iridium     ... 

Chromium 

Cr     51-7 

52-1 

Iron  

Cobalt       

Co    58-56 

59'o 

Krypton   ...     . 

Columbium 

Cb    93'3 

94 

Lanthanum 

(Niobium) 

Lead          ...     . 

H  =  i.      O  -  16. 

Cu    63-1  63-6 

E    164*8  166 

F      18*9  19 

Gd  155  156 

Ga    69-5  70 

Ge    71-9  72-5. 
Gl       9-03         9-1 

Au  195-7  i97'2 
He      4  4 

H        i  "ooo       i  '008 

In   113"!  114 

I     125*90  126*85 

Ir    191-5  i93'° 

Fe    55'5  55*9 

K      81-2  8r8 

La  137-9  138-9 

Pb  205-35  206*9 


120 


APPENDIX 


H-  i     0  =  16. 

H  =  i 

O  =   1  6. 

lyithium    

Li        6*98          7-03 

Selenium  .  .  . 

...  Se      78-6 

,    79'2 

Magnesium 

Mg   24-18       24.36 

Silicon 

...   Si      28-2 

28*4 

Manganese 

Mn   54-6         55-0 

Silver 

...   Ag  107-12 

107-93 

Mercury    

Hg  198*5           200'0 

Sodium 

...   Na    22-88 

23'05 

Molybdenum    .  . 

Mo    95-3         96-0 

Strontium 

...   Sr     86-94 

87-6 

Neodymium     .  .  . 

Ne  142-5       I43'6 

Sulphur    .  .  . 

...  S       31-83 

32-06 

Neon  

19-9         20 

Tantalum... 

...  Ta  i8r6 

183 

Nickel       ...      ... 

Ni     58-3       58-7 

Tellurium 

...  Te  126*6 

127*6 

Nitrogen  

N      13-93     i4'<>4 

Terbium   ... 

...  Tb  158-8 

1  60 

Osmium    

Os  189*6     191 

Thallium  ... 

...  Tl  202-6 

204-1 

Oxygen     

O    15-88       1  6  -oo 

Thorium  ... 

...  Th  230-8 

232*5 

Palladium 

Pd  105*7     IQ6'5 

Thulium  ... 

...  Tmi69'7 

171 

Phosphorus 

P      30'77     3i'o 

Tin    

...   Sn  nS'i 

119*0 

Platinum  

Pt    193-3     i94'8 

Titanium  ... 

...  Ti     477 

48-1 

Potassium         .  . 

K      38-86     39-15 

Tungsten  .  .  . 

...   W  182-6 

184-0 

Praseodymium.  .. 

Pr  139-4     140-5 

Uranium  ... 

...   U     236-7 

238-5 

Radium    

Ra  223-3     225 

Vanadium 

...  V      50-8 

51*2 

Rhodium  

Rh  102*2     103*0 

Xenon 

...  X    127 

128 

Rubidium  

Rb     84-8       85-4 

Ytterbium 

...  Yb  1717 

173*0 

Ruthenium 

Ru  100*9     ioi"7 

Yttrium    .  .  . 

...  Yt     88-3 

89*0 

Samarium 

Sm  148-9     150 

Zinc  

...   Zn     64-9 

65'4 

Scandium  

Sc     43-8       44-1 

Zirconium 

...   Zr     89-9 

90*6 

WEIGHTS   AND   MEASURES. 


The  unit  of  length  is  i  metre  =  39*37079  inches,  or  3*2809  feet,  or  1*0936 
yards. 

The  unit  of  volume  is  i  litre  =  *i    x    *i    x    'i  metre,  i.e.,    i   cubic  deci- 
metre. 

The  unit  of  weight  is  i  gramme  — -  wt.   of  i  cubic  centimetre  (*oi  m.)  of 
water  at  3*9°  C.   —  15*4325  troy  grains. 

Multiples  of  the  above — Kilo  —  1000.     Hecto  =  100.     Deka  —  10. 
Fractions  of  the  above — Deci  —  0*1.     Centi  —  0*01.     Milli  —  *ooi. 


121 


APPENDIX 


MEASURES   OF    LENGTH. 

i    micron  (/u.)  —  *ooi   m.m.   —   "00003937  or  roughly   1/25000  inch. 


i  m.m.  —  "03937  inch. 

i  centimetre,  c.m.  —  10  m.m.  — 
•394  inch. 

i  metre  —  1000  m.m.  —  39*371  in- 
ches =  3*2809  feet. 

i  kilometre  ==  1000  metres  —  1093  '6 
yards  =  '621  Eng.  mile. 


i  inch  —  25*400  m.m. 
i  inch  —  2*54  c.m. 

i  foot  =.  '3048  metre. 

i  yard  =  '9141  metre. 

i  Eng.  mile  =  1*610  kilometres. 


WEIGHTS. 


i  gram  r  :  15-432  grains  =:  "035  oz 
avoir.  —  '032  oz.  troy. 

i  kilogram  me  or  "kilo"  =  looogms- 
=  2*2046  Ibs.,  or  2-Jlbs.  avoir, 
(approximately). 

Metric  ton  or  1000  kilos  =  2204*62 
Ibs.  avoir. 


i  grain  —  '065  gram. 

i  oz.  avoir.  =  28*349  grams. 

i   oz.    troy  —  480   grs.    =   31  '1035 

grams. 

i  Ib.  troy  —  373*24  grams, 
i  Ib.  avoir.  =  453*584  grams, 
i  cwt.  =  50*0802  kilos. 


VOLUMES. 


i  litre  =  1000  c.c.  =  61*027   cubic  inches  =  1*760  or   i^   pints,  or  '220 

gallon  or  35*22  fluid  ozs. 

i   fluid  oz.  —  28*349  c.c.       i  pint  —  '5679  litre,      i  gall.  =  4*54346  litres, 
i  cubic  inch  ~  16*39  c.c.      i  cubic  foot  —  28*31531  litres. 


NOTES. 

To  convert  grams  to  grains  =  Log.  grams  -f  1*18843  =  log.  grains. 
To  convert  grains  into  grams  —  log.  grains  +  2*81157  =  log.   grams. 
To  convert  Fah.  degrees  to  centigrade,     f  ^-32). 

To  convert  Cent,  degrees  to  Fah.  (§  °C)  +  32,  or  multiply  the  °C  by  2,  sub- 
tract ^  and  add  32,  e.g.,  16*2  x  2  -  3*24  +  32  —  61*26  °F. 
i  litre  of  dry  H.  at  o°C.   and  760  m.m.  (or  Crith)  ==  '0896  gram, 
i  litre  of  dry  air  at  o°C  and  760  m.m.  pressure  —  1*2987  or  1*3  grams, 
i  gram  of  H  at  o°C  and  760  m.m.  pressure  =  11*16  litres. 
Sp.  gr.  of  air  ==  14*43.     H.  =  i. 
Coefficient  of  expansion  for  gases  =  ¥^F  or  0*003665. 
Parts  per  100,000  —-  grains  per  gall.  -4-  0*7 
Grains  per  gall.  =  grams  per  litre  x  70. 


122 


AgNOs 

As,03 

AuCla 

BaCla 

BaCO3 

Ba(OH)2 

Br  aq. 

CaCl2 

CaF, 

Ca(OH)2 

Ca3(P04)2 

CaSO4 

CHC13 

CO, 

cs, 

Cl  aq. 

Co2NO3 

CuO 

Cu(OH)2 

CuSO4 

Fed, 

FeSO4 

H2C4H406 

H2C204 

HC1 

HF 

HNO3 

H2PtCl6 

H2SO3 

H2S04 

H202 

HgCl2 

HgCy2 

Hg2N03 

HgN03 

KBr 

KBrO 

KC1 


APPENDIX 

FORMULA  OF  REAGENTS. 


Silver  nitrate. 

KC10 

,,      hypochlorite. 

Arsenious  oxide. 

KC1O3 

,,          chlorate. 

Gold  chloride. 

KaCO* 

,,         carbonate. 

Barium  chloride. 

K2Cr04 

,,         chromate. 

Barium  carbonate. 

K2Cr207       ... 

.    ,,         bichromate. 

Barium  hydroxide. 

KCy  (KCN).. 

Potassium  cyanide. 

Bromine  water. 

KCNS 
KHSO4 

,,       thiocyanate. 
,  ,         bisulphate. 

Calcium  chloride. 

K4FeCy6      ... 

,,      ferrocyanide. 

Calcium  fluoride. 

K,FeCy«      ... 

,,       ferricyanide. 

Calcium  hydroxide. 

KI 

,,         iodide. 

Calcium  phosphate. 

KMnO4 

,,   permanganate. 

Calcium  sulphate. 

KNO.2 

,,         nitrite. 

Chloroform. 

KN03 

,,         nitrate. 

Carbon  dioxide. 

KOH 

,,         hydroxide. 

Carbon  bisulphide. 

MgCl2 

Magnesium  chloride. 

Chlorine  water. 

MgS04 

Magnesium  sulphate. 

Cobalt  nitrate. 

MnO. 

Manganese  dioxide. 

Cupric  oxide. 

MnSO4 

Manganese  sulphate. 

Cupric  hydroxide. 

Na3AsO3      ... 

Sodium  arsenite. 

Cupric  sulphate. 

Na8AsO4      ... 

,,        arsenate. 

Ferric  chloride. 

NaCIO 

,,        hypochlorite. 

Ferrous  sulphate. 

Na2C03        ... 

,,        carbonate. 

Tartaric  acid. 

Na2FeNOCy5 

,,       nitroprusside. 

Oxalic  acid. 

NaHC03     ... 

,  ,        bicarbonate. 

Hydrochloric  acid. 

Na2HPO4    ... 

,,        phosphate. 

Hydrofluoric  acid. 

NaHSOs      ... 

,,        bisulphite. 

Nitric  acid. 

NaNOa 

,  ,        nitrite. 

Chloroplatinic  acid. 

NaOH 

,,        hydroxide. 

Sulphurous  acid. 

Na2S 

,,        sulphide. 

Sulphuric  acid. 

Na2SO3        ... 

,,        sulphite. 

Hydrogen    dioxide 

Na2S2O3       ... 

,,        thiosulphate. 

(hydroxyl). 

NH4C1 

Ammonium   chloride. 

Mercuric  chloride. 

(NH4)2C204... 

,,     oxalate. 

Mercuric  cyanide. 

CNH4)2C03  ... 

,,     carbonate. 

Mercuric  nitrate. 

(NH4)2Mo04  .. 

,,     molybdate. 

Mercurous  nitrate. 

NH4OH      ... 

,,     hydroxide. 

Potassium  bromide. 

(NH4)3P04  ... 

,,     phosphate. 

,,     hypobromite. 

NH4SH      J£| 

,,     hydrosulphide. 

,  ,         chloride. 

NiSO4 

Nickel  sulphate. 

Pb2C.2H3O,       Lead   acetate. 
Pb2NO8       ...   Lead  nitrate. 
PbS  ...   Lead  sulphide. 

PtCl4 
SH2 


. . .   Platinum  tetrachloride. 
...   Hydrogen  sulphide. 


APPENDIX 

SO, 

SbCl3 
SnCI2 
SrCl2 
ZnCL 


123 

Sulphur  dioxide. 
Antimony  trichloride. 
Stannous  chloride. 
Strontium  chloride. 
Zinc  chloride. 


INDEX. 


Page. 

Acids,  inorganic,  reactions  ...     35 

Acids,  organic,  reactions    ...  ...     44 

Acids,  preliminary  tests  for  ...   101 

Acids,  preparation  of  solution  ...   103 

Acids,  tables  for  detection  of  ...  104 

Acetic  acid              ...             ...  46,  112 

Acetone                   ...             ...  ...     58 

Acetaldehyde          ...  57,  m 

Acetanilide  (Antifebrin)     ...  ...     77 

Alcohol    ...             ...             ...  ...   in 

Alcohols  and  derivatives     ...  ...     55 

Alkalis,  in  silicates  ...  no 

Alkaloids,  general  precipitants  ...     70 

Alkaloids,  detection  of  single  ...     78 

Alloys  and  Metals                ...  ...     91 

Aluminium  reactions           ...  ...     15 

Ammonium  reactions           ...  ...     21 

Amyl  alcohol          ...             ...  ...     56 

Amyloids                 ...             ...  ...     64 

Aniline                    ...             ...  68,  112 

Antimony  reactions              ...  ...     13 

Antipyrine  ...     77 

Appendix                ...             ...  ...  in 

Aromatic  series      ...             ...  50,  67 

Arsenic  Group,  separation  ...  ...     95 

Arsenic,  reactions. .             ...  12,  13 

Atomic  Weights,  International,  list  of  119 

Atropine                  ...             ...  ...     71 

Barium  Group,  separation  ...  ...     99 

Barium,  reactions...             ...  ...     19 

Bases,  general  table  for  Separation  of    93 

Bases,  preparation  of  solution  ...     90 

Benzene                                  ...  67,  112 

Benzine  ...     67 

Benzoic  acid            ...             ...  50,106 

Beryllium  reactions             ...  ...     28 

Bismuth,  reactions               ...  ...     n 

Borax  bead  tests    ...             ...  ...     86 

Boric  acid  (Boracic  acid)     ...  ...     41 

British  gum            ...             ...  ...     64 

Bromic  acid  ...     37 

Brucine  ...     72 

Butyric  acid  ...     47 

Cacodyl  ...     46 

Cadmium  reactions              ...  ...     12 

Caesium  reactions                 ...  ...     34 

Caffeine                   ...             ...  ...     72 

Calcium  reactions                ...  ...     19 

Cane  sugar  ...     61 

Carbamide              ...             ...  ...     60 

Carbimide               ...             ...  ...     44 

Carbolic  acid          ...             ...  ...     67 

Carbohydrates       ...             ...  ...     61 

Carbon,  in  C  compounds    ...  ...  in 

Carbon  bisulphide                ...  59,  in 

Carbonic  acid         ...             ...  ...     43 


Cellulose 
Cerium  reactions 
Charcoal  tests 
Chloral  hydrate     ... 
Chloric  acid  reactions 
Chloroform 


Page. 

...  65 
...    28 

85,  87,  88 

57,  in 
36,  106,  107 

58,  in 


,,           test  for  impurities  .  .     58 

Chromic  acid  reactions  ...  ...     16 

Chromium  reactions  ...  ...     16 

Cinchonine             ...  ...  ...     73 

Citric  acid               ...  ...  ...     50 

Closed  tube  tests  ...  ...  82—85 

Cobalt  reactions    ...  ...  ...     18 

Cocaine                   ...  ...  ...     73 

Codeine                   ...  ...  ...     73 

Columbium  reactions  ...  ...     23 

Coniine                    ...  ...  ...     71 

Copper  reactions  ...  ...  ...     11 

Copper  Group,  separation  ...  ...     95 

Cyanic  acid             ...  ...  ...     44 

Daturine                  ...  ...  ...     71 

Dextrin                   ...  ...  ...     64 

Dextrose                  ...  ...  ...     61 

Didymium               ...  ...  ...     29 

Digitalin                  ...  ...  ...     66 

Double  cyanides    ...  ...  44,  no 

Elements  in  C  compounds  ...  ...   in 

Ether  (Ethyl  oxide)  ...  56,  112 

Ethyl  alcohol         ...  ...  55,  in 

Ethyl  acetate         ...  ...  ...   112 

Examination  for  Acids  ...  ...   101 

Examination  for  Bases  ...  ...     93 

Film  tests                ...  ...  ...     89 

Flame  colour  tests  ...  ...     86 

Fluosilicic  acid      ...  ...  ...     41 

Formalin                  ...  ...  ...     57 

Formaldehyde       ...  ...     57 

Formic  acid            ...  ...  46,112 

Formulae  of  Reagents  ...  ...  122 

Gallium  reactions  ...  ...     33 

Gallic  acid              ...  ...  ...     51 

Gallo-tannic  acid  ...  ...  ...     52 

General  Table  for  Bases  ...  ...     93 

Glucinum  reactions  ...  ...     28 

Glucoses                  ...  ...  ...     61 

Glucosides              ...  ...  ...     66 

Glycerol  (Glycerin)  59,  112 

Gold  reactions        ...  ...     24 

Grape  sugar            ...  ...     61 

Gum  Arabic            ...  ...65 

Halogens  in  C  compounds. .  ...  in 

Hippuric  acid         ...  ...  ...     54 

Hydriodic  acid      ...  37,  106 

Hydrobromic  acid . .  36,  106 

Hydrochloric  acid  35,  106 

Hydrocyanic  acid...  ...  44,  106 


124 


INDEX 


125 


Page. 

Hydroferricyanic  acid  ...  45,  107 

Hydro ferrocyanic  acid  ...  45,  107 

Hydrofluoric    acid  ...  ...  35 

Hydrofluosilicic  acid  ...  .  .  41 

Hydrogen  sulphide  ...  .  .  39 

Hydrogen  in  C  compounds  ...  in 

Hydroxyl  (Hydrogen  peroxide)       ...  59 

Hypochlorous  acid  ...  35,  107 

Hypophosphorous  acid  ...  •  •  43 

Indium,    reactions  ...  ...  32 

Inorganic  acids  ...  ...  35 

Insoluble  substances  ...  ...  108 

Inulin  (starch)  ...  ...  64 

lodic  acid  ...  ...  37 

Iridium  reactions  ...  ...  25 

Iron  reactions         ...  ...  ...  15 

Iron  Group,  separation  ...  ...  96 

Ketone     ..             ..  ...  ...  58 

Lactic  acid  ...  ...  50 

Lactose     .  .  ...  ...  62 

Laevulose  ...  ...  61 

Lanthanum  reactions  ...  ...  29 

Lead  reactions       ...  ...  ...  9 

Lithium  reactions...  ...  ...  21 

Magnesium  reactions  ...  ...  20 

Magnesium  Group,  separation  ...  100 

Malic  acid  ...  ...  49 

Maltose     .  .  ...  ...  62 

Manganese  reactions  ...  ...  17 

Match  tests  ...  ...  88 

Meconic  acid  ...  ...  53 

Mercury  reactions  ...  ...  10 

Metaboric  acid       .  .  ..'.  ...  41 

Metals  and  Alloys  ...  ...  91 

Metaphosphoric  acid  ...  ...  43 

Methyl  alcohol  ...  ...  55 

Milk  sugar  ...  ...  62 

Molybdenum  reactions  ...  ...  25 

Morphine  ...  ...  74 

Narcotine                ...  ...  ...  74 

Nickel  Group,  separation  ...  ...  98 

Nickel,    reactions  ...  ...  17 

Nicotine  ...  ...  71 

Niobium  reactions  ...  ...  23 

Nitric  acid  ...  ...  40 

Nitro  benzene         . .  ...  ...  112 

Nitrogen,  in  C  compounds  ...  in 

Nitroprusside  of  Sodium  ...  ...  40 

Nitrous  acid  ...  ...  40 

Non-volatile  solid  alkaloids  ...  71 

Organic  acids,  reactions  ...  ...  44 

Organic  liquids,  tests  for  ...  ...  in 

Osazones                 ...  ...  ...  63 

Osmium  reactions  ...  ...  23 

Oxalic  acid             ...  ...  ...  47 

Palladium  reactions  ...  ...  23 

Papaverine              ...  ...  ...  75 

Paraffin  oils             ...  ...  ...  112 

Perchloric  acid  reactions  ...  ...  36 

Peroxide  of  Hydrogen  ...  ...  59 

Phenacetin             ...  ...  ...  77 

Phenazone               ...  ...  ...  77 

Phenol      ...             ...  ...  ...  67 

Phenylamine          ...  ...  ...  68 

Phenyl  hydrazin,  reaction  for  sugars  63 


Page. 

Phosphates  Table,  separation  ...  97 

Phosphoric  acid  (ortho)      ...  ...  42 

Phosphorous  acid                 ...  ...  43 

Phosphorus  in  C  compounds  ...  in 

Platinum  reactions               ...  ...  25 

Potassium,  reactions            ...  ...  20 

Preliminary  Tests  for  Acids  ...  101 

Preliminary  Tests  for  Bases  81 — 90 

Preparation  of  the  Solution  ...  90 

Propionic  acid                      ...  ...  47 

Prussian  blue                        ...  ...  45 

Pyridine  ...             ...             ...  ...  68 

Pyroboric  acid  reactions    ...  ...  41 

Pyrogallol  (pyrogallic  acid)  ...  52 

Pyrophosphoric  acid            ...  ...  43 

Qualitative  Analysis  Tables  81 

Quinine                   ...             ...  ...  75 

Quinoline                ...             ...  ...  69 

Rarer  Metals  of  Group  I     ...  ...  21 

„      HB  ...  24 

„      HI  ...  28 

.,      IV  ...  31 

„      VI  ...  34 

Reagents — Liebermann's  ...  67 

,,            Preparation  of  ordinary...  115 

,,                     ,,                 special     ...  118 

,,            Dry      ...             ...  ...  119 

,,           Formulae  of       ...  ...  122 

Rubidium                ...             ...  ...  34 

Saccharose  (Sucrose)           ...  ...  61 

Salicin      ...             ...             ...  ...  66 

Salicylic  acid          ...             ...  ...  51 

Selenium  reactions              ...  ...  26 

Separation  of  Au  from  Pt  ...  ...  25 

BeO  from  A12O3  ...  28 

Li  in  waters...  ...  21 

Mo  in  minerals  ...  26 

Ni  from  Co  ...  ...  18 

Te          „      27 

U  in  minerals  ...  32 

Silica  and  Silicates              ...  ...  41 

Silicic  acid              ...             ...  ...  41 

Silicofluoric  acid    ...             ...  ...  41 

Silver,    reactions  ...             ...  ...  9 

Silver  Group,  separation     ...  ...  94 

Sodium  reactions ...             ...  ...  20 

Sodium  nitroprusside,  preparation  ...  40 

Solubilities,  Table  of          ...  ...  112 

Solution,  preparation  of,  for  analysis  90 

Spirit  of  Wine        ...             ...  ...  55 

Starch       ...             ...             ...  ...  64 

Strontium  reactions            ...  ...  19 

Strychnine              ...             ...  ...  76 

Succinic  acid          ...             ...  49,  106 

Sugar,  summary  of  reactions  ...  63 

Sulphine  (sulphuretted  hydrogen)  39  ,107 

Sulphocyanic  acid...             ...  ...  46 

Sulphur  in  C  compounds    ...  ...  in 

Sulphuric  acid        ...             ...  38,  107 

Sulphurous  acid     ...             ...  38,  107 

Table  of  Solubilities            ...  ...  112 

Tannic  acid            ...             ...  ...  52 

Tannin      ...             ...             ...  ...  52 

Tantalum,  reactions             ...  ...  31 

Tartaric,  distinction  from  Citric,  acid  49 


126 


INDEX 


Tartaric  acid 

Table  I — Separation  of  Bases 

II 

III 

IIlA 

IV 

V  ... 

VI  ... 
Tellurium  reactions 
Thallium  reactions 
Theine 

Thiocyanic  acid 
Thiosulphuric  acid 
Thorium  reactions 
Tin  reactions 
Titanium  reactions 


Page. 
.     48 

•  94 

•  95 
,     96 

9 


...  99 

...  loo 

...  27 

...  22 

...  72 

46,  107 

39,  io? 

...  30 

...  14 

...  30 


Tungsten  reactions 

Turnbull'sblue 

Turpentine 

Uranium,  reactions 

Urea 

Uric  acid  ... 

Vanadium,  reactions 

Vera  trine 

Volatile  bases 

Volatile  liquid  alkaloids 

Weights,  atomic    ... 

Weights  and  Measures 

Wolfram,  reactions 

Wood  spirit 

Zinc,   reactions 

Zirconium,  reactions 


Page. 

.  21 

•  45 

.  112 

•  31 
.  60 

•  53 

•  34 
.  76 
.  68 


120 
21 

55 
17 
29 


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